Provided by: spamassassin_3.4.4-1ubuntu1_all bug

NAME

       Mail::SpamAssassin::Conf - SpamAssassin configuration file

SYNOPSIS

         # a comment

         rewrite_header Subject          *****SPAM*****

         full PARA_A_2_C_OF_1618         /Paragraph .a.{0,10}2.{0,10}C. of S. 1618/i
         describe PARA_A_2_C_OF_1618     Claims compliance with senate bill 1618

         header FROM_HAS_MIXED_NUMS      From =~ /\d+[a-z]+\d+\S*@/i
         describe FROM_HAS_MIXED_NUMS    From: contains numbers mixed in with letters

         score A_HREF_TO_REMOVE          2.0

         lang es describe FROM_FORGED_HOTMAIL Forzado From: simula ser de hotmail.com

         lang pt_BR report O programa detetor de Spam ZOE [...]

DESCRIPTION

       SpamAssassin is configured using traditional UNIX-style configuration files, loaded from
       the "/usr/share/spamassassin" and "/etc/spamassassin" directories.

       The following web page lists the most important configuration settings used to configure
       SpamAssassin; novices are encouraged to read it first:

         http://wiki.apache.org/spamassassin/ImportantInitialConfigItems

FILE FORMAT

       The "#" character starts a comment, which continues until end of line.  NOTE: if the "#"
       character is to be used as part of a rule or configuration option, it must be escaped with
       a backslash.  i.e.: "\#"

       Whitespace in the files is not significant, but please note that starting a line with
       whitespace is deprecated, as we reserve its use for multi-line rule definitions, at some
       point in the future.

       Currently, each rule or configuration setting must fit on one-line; multi-line settings
       are not supported yet.

       File and directory paths can use "~" to refer to the user's home directory, but no other
       shell-style path extensions such as globing or "~user/" are supported.

       Where appropriate below, default values are listed in parentheses.

       Test names ("SYMBOLIC_TEST_NAME") can only contain alphanumerics/underscores, can not
       start with digit, and must be less than 128 characters.

USER PREFERENCES

       The following options can be used in both site-wide ("local.cf") and user-specific
       ("user_prefs") configuration files to customize how SpamAssassin handles incoming email
       messages.

   SCORING OPTIONS
       required_score n.nn (default: 5)
           Set the score required before a mail is considered spam.  "n.nn" can be an integer or
           a real number.  5.0 is the default setting, and is quite aggressive; it would be
           suitable for a single-user setup, but if you're an ISP installing SpamAssassin, you
           should probably set the default to be more conservative, like 8.0 or 10.0.  It is not
           recommended to automatically delete or discard messages marked as spam, as your users
           will complain, but if you choose to do so, only delete messages with an exceptionally
           high score such as 15.0 or higher. This option was previously known as "required_hits"
           and that name is still accepted, but is deprecated.

       score SYMBOLIC_TEST_NAME n.nn [ n.nn n.nn n.nn ]
           Assign scores (the number of points for a hit) to a given test.  Scores can be
           positive or negative real numbers or integers.  "SYMBOLIC_TEST_NAME" is the symbolic
           name used by SpamAssassin for that test; for example, 'FROM_ENDS_IN_NUMS'.

           If only one valid score is listed, then that score is always used for a test.

           If four valid scores are listed, then the score that is used depends on how
           SpamAssassin is being used. The first score is used when both Bayes and network tests
           are disabled (score set 0). The second score is used when Bayes is disabled, but
           network tests are enabled (score set 1). The third score is used when Bayes is enabled
           and network tests are disabled (score set 2). The fourth score is used when Bayes is
           enabled and network tests are enabled (score set 3).

           Setting a rule's score to 0 will disable that rule from running.

           If any of the score values are surrounded by parenthesis '()', then all of the scores
           in the line are considered to be relative to the already set score.  ie: '(3)' means
           increase the score for this rule by 3 points in all score sets.  '(3) (0) (3) (0)'
           means increase the score for this rule by 3 in score sets 0 and 2 only.

           If no score is given for a test by the end of the configuration, a default score is
           assigned: a score of 1.0 is used for all tests, except those whose names begin with
           'T_' (this is used to indicate a rule in testing) which receive 0.01.

           Note that test names which begin with '__' are indirect rules used to compose meta-
           match rules and can also act as prerequisites to other rules.  They are not scored or
           listed in the 'tests hit' reports, but assigning a score of 0 to an indirect rule will
           disable it from running.

   WHITELIST AND BLACKLIST OPTIONS
       whitelist_from user@example.com
           Used to whitelist sender addresses which send mail that is often tagged (incorrectly)
           as spam.

           Use of this setting is not recommended, since it blindly trusts the message, which is
           routinely and easily forged by spammers and phish senders. The recommended solution is
           to instead use "whitelist_auth" or other authenticated whitelisting methods, or
           "whitelist_from_rcvd".

           Whitelist and blacklist addresses are now file-glob-style patterns, so
           "friend@somewhere.com", "*@isp.com", or "*.domain.net" will all work.  Specifically,
           "*" and "?" are allowed, but all other metacharacters are not. Regular expressions are
           not used for security reasons.  Matching is case-insensitive.

           Multiple addresses per line, separated by spaces, is OK.  Multiple "whitelist_from"
           lines are also OK.

           The headers checked for whitelist addresses are as follows: if "Resent-From" is set,
           use that; otherwise check all addresses taken from the following set of headers:

                   Envelope-Sender
                   Resent-Sender
                   X-Envelope-From
                   From

           In addition, the "envelope sender" data, taken from the SMTP envelope data where this
           is available, is looked up.  See "envelope_sender_header".

           e.g.

             whitelist_from joe@example.com fred@example.com
             whitelist_from *@example.com

       unwhitelist_from user@example.com
           Used to override a default whitelist_from entry, so for example a distribution
           whitelist_from can be overridden in a local.cf file, or an individual user can
           override a whitelist_from entry in their own "user_prefs" file.  The specified email
           address has to match exactly (although case-insensitively) the address previously used
           in a whitelist_from line, which implies that a wildcard only matches literally the
           same wildcard (not 'any' address).

           e.g.

             unwhitelist_from joe@example.com fred@example.com
             unwhitelist_from *@example.com

       whitelist_from_rcvd addr@lists.sourceforge.net sourceforge.net
           Works similarly to whitelist_from, except that in addition to matching a sender
           address, a relay's rDNS name or its IP address must match too for the whitelisting
           rule to fire. The first parameter is a sender's e-mail address to whitelist, and the
           second is a string to match the relay's rDNS, or its IP address. Matching is case-
           insensitive.

           This second parameter is matched against a TCP-info information field as provided in a
           FROM clause of a trace information (i.e. in a Received header field, see RFC 5321).
           Only the Received header fields inserted by trusted hosts are considered. This
           parameter can either be a full hostname, or a domain component of that hostname, or an
           IP address (optionally followed by a slash and a prefix length) in square brackets.
           The address prefix (mask) length with a slash may stand within brackets along with an
           address, or may follow the bracketed address. Reverse DNS lookup is done by an MTA,
           not by SpamAssassin.

           For backward compatibility as an alternative to a CIDR notation, an IPv4 address in
           brackets may be truncated on classful boundaries to cover whole subnets, e.g.
           "[10.1.2.3]", "[10.1.2]", "[10.1]", "[10]".

           In other words, if the host that connected to your MX had an IP address 192.0.2.123
           that mapped to 'sendinghost.example.org', you should specify
           "sendinghost.example.org", or "example.org", or "[192.0.2.123]", or "[192.0.2.0/24]",
           or "[192.0.2]" here.

           Note that this requires that "internal_networks" be correct.  For simple cases, it
           will be, but for a complex network you may get better results by setting that
           parameter.

           It also requires that your mail exchangers be configured to perform DNS reverse
           lookups on the connecting host's IP address, and to record the result in the generated
           Received header field according to RFC 5321.

           e.g.

             whitelist_from_rcvd joe@example.com  example.com
             whitelist_from_rcvd *@*              mail.example.org
             whitelist_from_rcvd *@axkit.org      [192.0.2.123]
             whitelist_from_rcvd *@axkit.org      [192.0.2.0/24]
             whitelist_from_rcvd *@axkit.org      [192.0.2.0]/24
             whitelist_from_rcvd *@axkit.org      [2001:db8:1234::/48]
             whitelist_from_rcvd *@axkit.org      [2001:db8:1234::]/48

       def_whitelist_from_rcvd addr@lists.sourceforge.net sourceforge.net
           Same as "whitelist_from_rcvd", but used for the default whitelist entries in the
           SpamAssassin distribution.  The whitelist score is lower, because these are often
           targets for spammer spoofing.

       whitelist_allows_relays user@example.com
           Specify addresses which are in "whitelist_from_rcvd" that sometimes send through a
           mail relay other than the listed ones. By default mail with a From address that is in
           "whitelist_from_rcvd" that does not match the relay will trigger a forgery rule.
           Including the address in "whitelist_allows_relay" prevents that.

           Whitelist and blacklist addresses are now file-glob-style patterns, so
           "friend@somewhere.com", "*@isp.com", or "*.domain.net" will all work.  Specifically,
           "*" and "?" are allowed, but all other metacharacters are not. Regular expressions are
           not used for security reasons.  Matching is case-insensitive.

           Multiple addresses per line, separated by spaces, is OK.  Multiple
           "whitelist_allows_relays" lines are also OK.

           The specified email address does not have to match exactly the address previously used
           in a whitelist_from_rcvd line as it is compared to the address in the header.

           e.g.

             whitelist_allows_relays joe@example.com fred@example.com
             whitelist_allows_relays *@example.com

       unwhitelist_from_rcvd user@example.com
           Used to override a default whitelist_from_rcvd entry, so for example a distribution
           whitelist_from_rcvd can be overridden in a local.cf file, or an individual user can
           override a whitelist_from_rcvd entry in their own "user_prefs" file.

           The specified email address has to match exactly the address previously used in a
           whitelist_from_rcvd line.

           e.g.

             unwhitelist_from_rcvd joe@example.com fred@example.com
             unwhitelist_from_rcvd *@axkit.org

       blacklist_from user@example.com
           Used to specify addresses which send mail that is often tagged (incorrectly) as non-
           spam, but which the user doesn't want.  Same format as "whitelist_from".

       unblacklist_from user@example.com
           Used to override a default blacklist_from entry, so for example a distribution
           blacklist_from can be overridden in a local.cf file, or an individual user can
           override a blacklist_from entry in their own "user_prefs" file. The specified email
           address has to match exactly the address previously used in a blacklist_from line.

           e.g.

             unblacklist_from joe@example.com fred@example.com
             unblacklist_from *@spammer.com

       whitelist_to user@example.com
           If the given address appears as a recipient in the message headers (Resent-To, To, Cc,
           obvious envelope recipient, etc.) the mail will be whitelisted.  Useful if you're
           deploying SpamAssassin system-wide, and don't want some users to have their mail
           filtered.  Same format as "whitelist_from".

           There are three levels of To-whitelisting, "whitelist_to", "more_spam_to" and
           "all_spam_to".  Users in the first level may still get some spammish mails blocked,
           but users in "all_spam_to" should never get mail blocked.

           The headers checked for whitelist addresses are as follows: if "Resent-To" or
           "Resent-Cc" are set, use those; otherwise check all addresses taken from the following
           set of headers:

                   To
                   Cc
                   Apparently-To
                   Delivered-To
                   Envelope-Recipients
                   Apparently-Resent-To
                   X-Envelope-To
                   Envelope-To
                   X-Delivered-To
                   X-Original-To
                   X-Rcpt-To
                   X-Real-To

       more_spam_to user@example.com
           See above.

       all_spam_to user@example.com
           See above.

       blacklist_to user@example.com
           If the given address appears as a recipient in the message headers (Resent-To, To, Cc,
           obvious envelope recipient, etc.) the mail will be blacklisted.  Same format as
           "blacklist_from".

       whitelist_auth user@example.com
           Used to specify addresses which send mail that is often tagged (incorrectly) as spam.
           This is different from "whitelist_from" and "whitelist_from_rcvd" in that it first
           verifies that the message was sent by an authorized sender for the address, before
           whitelisting.

           Authorization is performed using one of the installed sender-authorization schemes:
           SPF (using "Mail::SpamAssassin::Plugin::SPF"), or DKIM (using
           "Mail::SpamAssassin::Plugin::DKIM").  Note that those plugins must be active, and
           working, for this to operate.

           Using "whitelist_auth" is roughly equivalent to specifying duplicate
           "whitelist_from_spf", "whitelist_from_dk", and "whitelist_from_dkim" lines for each of
           the addresses specified.

           e.g.

             whitelist_auth joe@example.com fred@example.com
             whitelist_auth *@example.com

       def_whitelist_auth user@example.com
           Same as "whitelist_auth", but used for the default whitelist entries in the
           SpamAssassin distribution.  The whitelist score is lower, because these are often
           targets for spammer spoofing.

       unwhitelist_auth user@example.com
           Used to override a "whitelist_auth" entry. The specified email address has to match
           exactly the address previously used in a "whitelist_auth" line.

           e.g.

             unwhitelist_auth joe@example.com fred@example.com
             unwhitelist_auth *@example.com

       enlist_uri_host (listname) host ...
           Adds one or more host names or domain names to a named list of URI domains.  The named
           list can then be consulted through a check_uri_host_listed() eval rule implemented by
           the WLBLEval plugin, which takes the list name as an argument. Parenthesis around a
           list name are literal - a required syntax.

           Host names may optionally be prefixed by an exclamation mark '!', which produces false
           as a result if this entry matches. This makes it easier to exclude some subdomains
           when their superdomain is listed, for example:

             enlist_uri_host (MYLIST) !sub1.example.com !sub2.example.com example.com

           No wildcards are supported, but subdomains do match implicitly. Lists are independent.
           Search for each named list starts by looking up the full hostname first, then leading
           fields are progressively stripped off (e.g.: sub.example.com, example.com, com) until
           a match is found or we run out of fields. The first matching entry (the most specific)
           determines if a lookup yielded a true (no '!' prefix) or a false (with a '!' prefix)
           result.

           If an URL found in a message contains an IP address in place of a host name, the given
           list must specify the exact same IP address (instead of a host name) in order to
           match.

           Use the delist_uri_host directive to neutralize previous enlist_uri_host settings.

           Enlisting to lists named 'BLACK' and 'WHITE' have their shorthand directives
           blacklist_uri_host and whitelist_uri_host and corresponding default rules, but the
           names 'BLACK' and 'WHITE' are otherwise not special or reserved.

       delist_uri_host [ (listname) ] host ...
           Removes one or more specified host names from a named list of URI domains.  Removing
           an unlisted name is ignored (is not an error). Listname is optional, if specified then
           just the named list is affected, otherwise hosts are removed from all URI host lists
           created so far. Parenthesis around a list name are a required syntax.

           Note that directives in configuration files are processed in sequence, the
           delist_uri_host only applies to previously listed entries and has no effect on
           enlisted entries in yet-to-be-processed directives.

           For convenience (similarity to the enlist_uri_host directive) hostnames may be
           prefixed by a an exclamation mark, which is stripped off from each name and has no
           meaning here.

       enlist_addrlist (listname) user@example.com
           Adds one or more addresses to a named list of addresses.  The named list can then be
           consulted through a check_from_in_list() or a check_to_in_list() eval rule implemented
           by the WLBLEval plugin, which takes the list name as an argument. Parenthesis around a
           list name are literal - a required syntax.

           Listed addresses are file-glob-style patterns, so "friend@somewhere.com", "*@isp.com",
           or "*.domain.net" will all work.  Specifically, "*" and "?" are allowed, but all other
           metacharacters are not. Regular expressions are not used for security reasons.
           Matching is case-insensitive.

           Multiple addresses per line, separated by spaces, is OK.  Multiple "enlist_addrlist"
           lines are also OK.

           Enlisting an address to the list named blacklist_to is synonymous to using the
           directive blacklist_to

           Enlisting an address to the list named blacklist_from is synonymous to using the
           directive blacklist_from

           Enlisting an address to the list named whitelist_to is synonymous to using the
           directive whitelist_to

           Enlisting an address to the list named whitelist_from is synonymous to using the
           directive whitelist_from

           e.g.

             enlist_addrlist (PAYPAL_ADDRESS) service@paypal.com
             enlist_addrlist (PAYPAL_ADDRESS) *@paypal.co.uk

       blacklist_uri_host host-or-domain ...
           Is a shorthand for a directive:  enlist_uri_host (BLACK) host ...

           Please see directives enlist_uri_host and delist_uri_host for details.

       whitelist_uri_host host-or-domain ...
           Is a shorthand for a directive:  enlist_uri_host (BLACK) host ...

           Please see directives enlist_uri_host and delist_uri_host for details.

   BASIC MESSAGE TAGGING OPTIONS
       rewrite_header { subject | from | to } STRING
           By default, suspected spam messages will not have the "Subject", "From" or "To" lines
           tagged to indicate spam. By setting this option, the header will be tagged with
           "STRING" to indicate that a message is spam. For the From or To headers, this will
           take the form of an RFC 2822 comment following the address in parentheses. For the
           Subject header, this will be prepended to the original subject. Note that you should
           only use the _REQD_ and _SCORE_ tags when rewriting the Subject header if
           "report_safe" is 0. Otherwise, you may not be able to remove the SpamAssassin markup
           via the normal methods.  More information about tags is explained below in the
           TEMPLATE TAGS section.

           Parentheses are not permitted in STRING if rewriting the From or To headers.  (They
           will be converted to square brackets.)

           If "rewrite_header subject" is used, but the message being rewritten does not already
           contain a "Subject" header, one will be created.

           A null value for "STRING" will remove any existing rewrite for the specified header.

       subjprefix
           Add a prefix in emails Subject if a rule is matched.  To enable this option
           "rewrite_header Subject" config option must be enabled as well.

           The check "if can(Mail::SpamAssassin::Conf::feature_subjprefix)" should be used to
           silence warnings in previous SpamAssassin versions.

           To be able to use this feature a "add_header all Subjprefix _SUBJPREFIX_"
           configuration line could be needed on some setups.

       add_header { spam | ham | all } header_name string
           Customized headers can be added to the specified type of messages (spam, ham, or "all"
           to add to either).  All headers begin with "X-Spam-" (so a "header_name" Foo will
           generate a header called X-Spam-Foo).  header_name is restricted to the character set
           [A-Za-z0-9_-].

           The order of "add_header" configuration options is preserved, inserted headers will
           follow this order of declarations. When combining "add_header" with "clear_headers"
           and "remove_header", keep in mind that "add_header" appends a new header to the
           current list, after first removing any existing header fields of the same name. Note
           also that "add_header", "clear_headers" and "remove_header" may appear in multiple .cf
           files, which are interpreted in alphabetic order.

           "string" can contain tags as explained below in the TEMPLATE TAGS section.  You can
           also use "\n" and "\t" in the header to add newlines and tabulators as desired.  A
           backslash has to be written as \\, any other escaped chars will be silently removed.

           All headers will be folded if fold_headers is set to 1. Note: Manually adding newlines
           via "\n" disables any further automatic wrapping (ie: long header lines are possible).
           The lines will still be properly folded (marked as continuing) though.

           You can customize existing headers with add_header (only the specified subset of
           messages will be changed).

           See also "clear_headers" and "remove_header" for removing headers.

           Here are some examples (these are the defaults, note that Checker-Version can not be
           changed or removed):

             add_header spam Flag _YESNOCAPS_
             add_header all Status _YESNO_, score=_SCORE_ required=_REQD_ tests=_TESTS_ autolearn=_AUTOLEARN_ version=_VERSION_
             add_header all Level _STARS(*)_
             add_header all Checker-Version SpamAssassin _VERSION_ (_SUBVERSION_) on _HOSTNAME_

       remove_header { spam | ham | all } header_name
           Headers can be removed from the specified type of messages (spam, ham, or "all" to
           remove from either).  All headers begin with "X-Spam-" (so "header_name" will be
           appended to "X-Spam-").

           See also "clear_headers" for removing all the headers at once.

           Note that X-Spam-Checker-Version is not removable because the version information is
           needed by mail administrators and developers to debug problems.  Without at least one
           header, it might not even be possible to determine that SpamAssassin is running.

       clear_headers
           Clear the list of headers to be added to messages.  You may use this before any
           add_header options to prevent the default headers from being added to the message.

           "add_header", "clear_headers" and "remove_header" may appear in multiple .cf files,
           which are interpreted in alphabetic order, so "clear_headers" in a later file will
           remove all added headers from previously interpreted configuration files, which may or
           may not be desired.

           Note that X-Spam-Checker-Version is not removable because the version information is
           needed by mail administrators and developers to debug problems.  Without at least one
           header, it might not even be possible to determine that SpamAssassin is running.

       report_safe ( 0 | 1 | 2 )     (default: 1)
           if this option is set to 1, if an incoming message is tagged as spam, instead of
           modifying the original message, SpamAssassin will create a new report message and
           attach the original message as a message/rfc822 MIME part (ensuring the original
           message is completely preserved, not easily opened, and easier to recover).

           If this option is set to 2, then original messages will be attached with a content
           type of text/plain instead of message/rfc822.  This setting may be required for safety
           reasons on certain broken mail clients that automatically load attachments without any
           action by the user.  This setting may also make it somewhat more difficult to extract
           or view the original message.

           If this option is set to 0, incoming spam is only modified by adding some "X-Spam-"
           headers and no changes will be made to the body.  In addition, a header named X-Spam-
           Report will be added to spam.  You can use the remove_header option to remove that
           header after setting report_safe to 0.

           See report_safe_copy_headers if you want to copy headers from the original mail into
           tagged messages.

       report_wrap_width (default: 70)
           This option sets the wrap width for description lines in the X-Spam-Report header, not
           accounting for tab width.

   LANGUAGE OPTIONS
       ok_locales xx [ yy zz ... ]        (default: all)
           This option is used to specify which locales are considered OK for incoming mail.
           Mail using the character sets that are allowed by this option will not be marked as
           possibly being spam in a foreign language.

           If you receive lots of spam in foreign languages, and never get any non-spam in these
           languages, this may help.  Note that all ISO-8859-* character sets, and Windows code
           page character sets, are always permitted by default.

           Set this to "all" to allow all character sets.  This is the default.

           The rules "CHARSET_FARAWAY", "CHARSET_FARAWAY_BODY", and "CHARSET_FARAWAY_HEADERS" are
           triggered based on how this is set.

           Examples:

             ok_locales all         (allow all locales)
             ok_locales en          (only allow English)
             ok_locales en ja zh    (allow English, Japanese, and Chinese)

           Note: if there are multiple ok_locales lines, only the last one is used.

           Select the locales to allow from the list below:

           en   - Western character sets in general
           ja   - Japanese character sets
           ko   - Korean character sets
           ru   - Cyrillic character sets
           th   - Thai character sets
           zh   - Chinese (both simplified and traditional) character sets
       normalize_charset ( 0 | 1)        (default: 0)
           Whether to decode non- UTF-8 and non-ASCII textual parts and recode them to UTF-8
           before the text is given over to rules processing. The character set used for
           attempted decoding is primarily based on a declared character set in a Content-Type
           header, but if the decoding attempt fails a module Encode::Detect::Detector is
           consulted (if available) to provide a guess based on the actual text, and decoding is
           re-attempted. Even if the option is enabled no unnecessary decoding and re-encoding
           work is done when possible (like with an all-ASCII text with a US-ASCII or extended
           ASCII character set declaration, e.g. UTF-8 or ISO-8859-nn or Windows-nnnn).

           Unicode support in old versions of perl or in a core module Encode is likely to be
           buggy in places, so if the normalize_charset function is enabled it is advised to
           stick to more recent versions of perl (preferably 5.12 or later). The module
           Encode::Detect::Detector is optional, when necessary it will be used if it is
           available.

       body_part_scan_size               (default: 50000)
           Per mime-part scan size limit in bytes for "body" type rules.  The decoded/stripped
           mime-part is truncated approx to this size.  Helps scanning large messages safely, so
           it's not necessary to skip them completely. Disabled with 0.

       rawbody_part_scan_size               (default: 500000)
           Like body_part_scan_size, for "rawbody" type rules.

   NETWORK TEST OPTIONS
       trusted_networks IPaddress[/masklen] ...   (default: none)
           What networks or hosts are 'trusted' in your setup.  Trusted in this case means that
           relay hosts on these networks are considered to not be potentially operated by
           spammers, open relays, or open proxies.  A trusted host could conceivably relay spam,
           but will not originate it, and will not forge header data. DNS blacklist checks will
           never query for hosts on these networks.

           See "http://wiki.apache.org/spamassassin/TrustPath" for more information.

           MXes for your domain(s) and internal relays should also be specified using the
           "internal_networks" setting. When there are 'trusted' hosts that are not MXes or
           internal relays for your domain(s) they should only be specified in
           "trusted_networks".

           The "IPaddress" can be an IPv4 address (in a dot-quad form), or an IPv6 address
           optionally enclosed in square brackets. Scoped link-local IPv6 addresses are
           syntactically recognized but the interface scope is currently ignored (e.g.
           [fe80::1234%eth0] ) and should be avoided.

           If a "/masklen" is specified, it is considered a CIDR-style 'netmask' length,
           specified in bits.  If it is not specified, but less than 4 octets of an IPv4 address
           are specified with a trailing dot, an implied netmask length covers all addresses in
           remaining octets (i.e. implied masklen is /8 or /16 or /24).  If masklen is not
           specified, and there is not trailing dot, then just a single IP address specified is
           used, as if the masklen were "/32" with an IPv4 address, or "/128" in case of an IPv6
           address.

           If a network or host address is prefaced by a "!" the matching network or host will be
           excluded from the list even if a less specific (shorter netmask length) subnet is
           later specified in the list. This allows a subset of a wider network to be exempt. In
           case of specifying overlapping subnets, specify more specific subnets first (tighter
           matching, i.e. with a longer netmask length), followed by less specific (shorter
           netmask length) subnets to get predictable results regardless of the search algorithm
           used - when Net::Patricia module is installed the search finds the tightest matching
           entry in the list, while a sequential search as used in absence of the module
           Net::Patricia will find the first matching entry in the list.

           Note: 127.0.0.0/8 and ::1 are always included in trusted_networks, regardless of your
           config.

           Examples:

              trusted_networks 192.168.0.0/16        # all in 192.168.*.*
              trusted_networks 192.168.              # all in 192.168.*.*
              trusted_networks 212.17.35.15          # just that host
              trusted_networks !10.0.1.5 10.0.1/24   # all in 10.0.1.* but not 10.0.1.5
              trusted_networks 2001:db8:1::1 !2001:db8:1::/64 2001:db8::/32
                # 2001:db8::/32 and 2001:db8:1::1/128, except the rest of 2001:db8:1::/64

           This operates additively, so a "trusted_networks" line after another one will append
           new entries to the list of trusted networks.  To clear out the existing entries, use
           "clear_trusted_networks".

           If "trusted_networks" is not set and "internal_networks" is, the value of
           "internal_networks" will be used for this parameter.

           If neither "trusted_networks" or "internal_networks" is set, a basic inference
           algorithm is applied.  This works as follows:

           ·   If the 'from' host has an IP address in a private (RFC 1918) network range, then
               it's trusted

           ·   If there are authentication tokens in the received header, and the previous host
               was trusted, then this host is also trusted

           ·   Otherwise this host, and all further hosts, are consider untrusted.

       clear_trusted_networks
           Empty the list of trusted networks.

       internal_networks IPaddress[/masklen] ...   (default: none)
           What networks or hosts are 'internal' in your setup.   Internal means that relay hosts
           on these networks are considered to be MXes for your domain(s), or internal relays.
           This uses the same syntax as "trusted_networks", above - see there for details.

           This value is used when checking 'dial-up' or dynamic IP address blocklists, in order
           to detect direct-to-MX spamming.

           Trusted relays that accept mail directly from dial-up connections (i.e. are also
           performing a role of mail submission agents - MSA) should not be listed in
           "internal_networks". List them only in "trusted_networks".

           If "trusted_networks" is set and "internal_networks" is not, the value of
           "trusted_networks" will be used for this parameter.

           If neither "trusted_networks" nor "internal_networks" is set, no addresses will be
           considered local; in other words, any relays past the machine where SpamAssassin is
           running will be considered external.

           Every entry in "internal_networks" must appear in "trusted_networks"; in other words,
           "internal_networks" is always a subset of the trusted set.

           Note: 127/8 and ::1 are always included in internal_networks, regardless of your
           config.

       clear_internal_networks
           Empty the list of internal networks.

       msa_networks IPaddress[/masklen] ...   (default: none)
           The networks or hosts which are acting as MSAs in your setup (but not also as MX
           relays). This uses the same syntax as "trusted_networks", above - see there for
           details.

           MSA means that the relay hosts on these networks accept mail from your own users and
           authenticates them appropriately.  These relays will never accept mail from hosts that
           aren't authenticated in some way. Examples of authentication include, IP lists, SMTP
           AUTH, POP-before-SMTP, etc.

           All relays found in the message headers after the MSA relay will take on the same
           trusted and internal classifications as the MSA relay itself, as defined by your
           trusted_networks and internal_networks configuration.

           For example, if the MSA relay is trusted and internal so will all of the relays that
           precede it.

           When using msa_networks to identify an MSA it is recommended that you treat that MSA
           as both trusted and internal.  When an MSA is not included in msa_networks you should
           treat the MSA as trusted but not internal, however if the MSA is also acting as an MX
           or intermediate relay you must always treat it as both trusted and internal and ensure
           that the MSA includes visible auth tokens in its Received header to identify
           submission clients.

           Warning: Never include an MSA that also acts as an MX (or is also an intermediate
           relay for an MX) or otherwise accepts mail from non-authenticated users in
           msa_networks.  Doing so will result in unknown external relays being trusted.

       clear_msa_networks
           Empty the list of msa networks.

       originating_ip_headers header ...   (default: X-Yahoo-Post-IP X-Originating-IP
       X-Apparently-From X-SenderIP)
           A list of header field names from which an originating IP address can be obtained. For
           example, webmail servers may record a client IP address in X-Originating-IP.

           These IP addresses are virtually appended into the Received: chain, so they are used
           in RBL checks where appropriate.

           Currently the IP addresses are not added into X-Spam-Relays-* header fields, but they
           may be in the future.

       clear_originating_ip_headers
           Empty the list of 'originating IP address' header field names.

       always_trust_envelope_sender ( 0 | 1 )   (default: 0)
           Trust the envelope sender even if the message has been passed through one or more
           trusted relays.  See also "envelope_sender_header".

       skip_rbl_checks ( 0 | 1 )   (default: 0)
           Turning on the skip_rbl_checks setting will disable the DNSEval plugin, which
           implements Real-time Block List (or: Blackhole List) (RBL) lookups.

           By default, SpamAssassin will run RBL checks. Individual blocklists may be disabled
           selectively by setting a score of a corresponding rule to 0.

           See also a related configuration parameter skip_uribl_checks, which controls the
           URIDNSBL plugin (documented in the URIDNSBL man page).

       dns_available { yes | no | test[: domain1 domain2...] }   (default: yes)
           Tells SpamAssassin whether DNS resolving is available or not. A value yes indicates
           DNS resolving is available, a value no indicates DNS resolving is not available - both
           of these values apply unconditionally and skip initial DNS tests, which can be slow or
           unreliable.

           When the option value is a test (with or without arguments), SpamAssassin will query
           some domain names on the internet during initialization, attempting to determine if
           DNS resolving is working or not. A space-separated list of domain names may be
           specified explicitly, or left to a built-in default of a dozen or so domain names.
           From an explicit or a default list a subset of three domain names is picked randomly
           for checking. The test queries for NS records of these domain: if at least one query
           returns a success then SpamAssassin considers DNS resolving as available, otherwise
           not.

           The problem is that the test can introduce some startup delay if a network connection
           is down, and in some cases it can wrongly guess that DNS is unavailable because a test
           connection failed, what causes disabling several DNS-dependent tests.

           Please note, the DNS test queries for NS records, so specify domain names, not host
           names.

           Since version 3.4.0 of SpamAssassin a default setting for option dns_available is yes.
           A default in older versions was test.

       dns_server ip-addr-port  (default: entries provided by Net::DNS)
           Specifies an IP address of a DNS server, and optionally its port number.  The
           dns_server directive may be specified multiple times, each entry adding to a list of
           available resolving name servers. The ip-addr-port argument can either be an IPv4 or
           IPv6 address, optionally enclosed in brackets, and optionally followed by a colon and
           a port number. In absence of a port number a standard port number 53 is assumed. When
           an IPv6 address is specified along with a port number, the address must be enclosed in
           brackets to avoid parsing ambiguity regarding a colon separator. A scoped link-local
           IP address is allowed (assuming underlying modules allow it).

           Examples :
            dns_server 127.0.0.1
            dns_server 127.0.0.1:53
            dns_server [127.0.0.1]:53
            dns_server [::1]:53
            dns_server fe80::1%lo0
            dns_server [fe80::1%lo0]:53

           In absence of dns_server directives, the list of name servers is provided by Net::DNS
           module, which typically obtains the list from /etc/resolv.conf, but this may be
           platform dependent. Please consult the Net::DNS::Resolver documentation for details.

       clear_dns_servers
           Empty the list of explicitly configured DNS servers through a dns_server directive,
           falling back to Net::DNS -supplied defaults.

       dns_local_ports_permit ranges...
           Add the specified ports or ports ranges to the set of allowed port numbers that can be
           used as local port numbers when sending DNS queries to a resolver.

           The argument is a whitespace-separated or a comma-separated list of single port
           numbers n, or port number pairs (i.e. m-n) delimited by a '-', representing a range.
           Allowed port numbers are between 1 and 65535.

           Directives dns_local_ports_permit and dns_local_ports_avoid are processed in order in
           which they appear in configuration files. Each directive adds (or subtracts) its
           subsets of ports to a current set of available ports.  Whatever is left in the set by
           the end of configuration processing is made available to a DNS resolving client code.

           If the resulting set of port numbers is empty (see also the directive
           dns_local_ports_none), then SpamAssassin does not apply its ports randomization logic,
           but instead leaves the operating system to choose a suitable free local port number.

           The initial set consists of all port numbers in the range 1024-65535.  Note that
           system config files already modify the set and remove all the IANA registered port
           numbers and some other ranges, so there is rarely a need to adjust the ranges by site-
           specific directives.

           See also directives dns_local_ports_permit and dns_local_ports_none.

       dns_local_ports_avoid ranges...
           Remove specified ports or ports ranges from the set of allowed port numbers that can
           be used as local port numbers when sending DNS queries to a resolver.

           Please see directive dns_local_ports_permit for details.

       dns_local_ports_none
           Is a fast shorthand for:

             dns_local_ports_avoid 1-65535

           leaving the set of available DNS query local port numbers empty. In all respects
           (apart from speed) it is equivalent to the shown directive, and can be freely mixed
           with dns_local_ports_permit and dns_local_ports_avoid.

           If the resulting set of port numbers is empty, then SpamAssassin does not apply its
           ports randomization logic, but instead leaves the operating system to choose a
           suitable free local port number.

           See also directives dns_local_ports_permit and dns_local_ports_avoid.

       dns_test_interval n   (default: 600 seconds)
           If dns_available is set to test, the dns_test_interval time in number of seconds will
           tell SpamAssassin how often to retest for working DNS.  A numeric value is optionally
           suffixed by a time unit (s, m, h, d, w, indicating seconds (default), minutes, hours,
           days, weeks).

       dns_options opts   (default: norotate, nodns0x20, edns=4096)
           Provides a (whitespace or comma -separated) list of options applying to DNS resolving.
           Available options are: rotate, dns0x20 and edns (or edns0). Option name may be negated
           by prepending a no (e.g. norotate, NoEDNS) to counteract a previously enabled option.
           Option names are not case-sensitive. The dns_options directive may appear in
           configuration files multiple times, the last setting prevails.

           Option edns (or edsn0) may take a value which specifies a requestor's acceptable UDP
           payload size according to EDNS0 specifications (RFC 6891, ex RFC 2671) e.g. edns=4096.
           When EDNS0 is off (noedns or edns=512) a traditional implied UDP payload size is 512
           bytes, which is also a minimum allowed value for this option. When the option is
           specified but a value is not provided, a conservative default of 1220 bytes is
           implied. It is recommended to keep edns enabled when using a local recursive DNS
           server which supports EDNS0 (like most modern DNS servers do), a suitable setting in
           this case is edns=4096, which is also a default. Allowing UDP payload size larger than
           512 bytes can avoid truncation of resource records in large DNS responses (like in TXT
           records of some SPF and DKIM responses, or when an unreasonable number of A records is
           published by some domain). The option should be disabled when a recursive DNS server
           is only reachable through non- RFC 6891 compliant middleboxes (such as some old-
           fashioned firewall) which bans DNS UDP payload sizes larger than 512 bytes. A suitable
           value when a non-local recursive DNS server is used and a middlebox does allow EDNS0
           but blocks fragmented IP packets is perhaps 1220 bytes, allowing a DNS UDP packet to
           fit within a single IP packet in most cases (a slightly less conservative range would
           be 1280-1410 bytes).

           Option rotate causes SpamAssassin to choose a DNS server at random from all servers
           listed in "/etc/resolv.conf" every dns_test_interval seconds, effectively spreading
           the load over all currently available DNS servers when there are many spamd workers.

           Option dns0x20 enables randomization of letters in a DNS query label according to
           draft-vixie-dnsext-dns0x20, decreasing a chance of collisions of responses (by chance
           or by a malicious intent) by increasing spread as provided by a 16-bit query ID and up
           to 16 bits of a port number, with additional bits as encoded by flipping case
           (upper/lower) of letters in a query. The number of additional random bits corresponds
           to the number of letters in a query label. Should work reliably with all mainstream
           DNS servers - do not turn on if you see frequent info messages "dns: no callback for
           id:" in the log, or if RBL or URIDNS lookups do not work for no apparent reason.

       dns_query_restriction (allow|deny) domain1 domain2 ...
           Option allows disabling of rules which would result in a DNS query to one of the
           listed domains. The first argument must be a literal "allow" or "deny", remaining
           arguments are domains names.

           Most DNS queries (with some exceptions) are subject to dns_query_restriction.  A
           domain to be queried is successively stripped-off of its leading labels (thus yielding
           a series of its parent domains), and on each iteration a check is made against an
           associative array generated by dns_query_restriction options. Search stops at the
           first match (i.e. the tightest match), and the matching entry with its "allow" or
           "deny" value then controls whether a DNS query is allowed to be launched.

           If no match is found an implicit default is to allow a query. The purpose of an
           explicit "allow" entry is to be able to override a previously configured "deny" on the
           same domain or to override an entry (possibly yet to be configured in subsequent
           config directives) on one of its parent domains.  Thus an 'allow zen.spamhaus.org'
           with a 'deny spamhaus.org' would permit DNS queries on a specific DNS BL zone but deny
           queries to other zones under the same parent domain.

           Domains are matched case-insensitively, no wildcards are recognized, there should be
           no leading or trailing dot.

           Specifying a block on querying a domain name has a similar effect as setting a score
           of corresponding DNSBL and URIBL rules to zero, and can be a handy alternative to
           hunting for such rules when a site policy does not allow certain DNS block lists to be
           queried.

           Example:
             dns_query_restriction deny  dnswl.org surbl.org
             dns_query_restriction allow zen.spamhaus.org
             dns_query_restriction deny  spamhaus.org mailspike.net spamcop.net

       clear_dns_query_restriction
           The option removes any entries entered by previous 'dns_query_restriction' options,
           leaving the list empty, i.e. allowing DNS queries for any domain (including any DNS BL
           zone).

   LEARNING OPTIONS
       use_learner ( 0 | 1 )         (default: 1)
           Whether to use any machine-learning classifiers with SpamAssassin, such as the default
           'BAYES_*' rules.  Setting this to 0 will disable use of any and all human-trained
           classifiers.

       use_bayes ( 0 | 1 )      (default: 1)
           Whether to use the naive-Bayesian-style classifier built into SpamAssassin.  This is a
           master on/off switch for all Bayes-related operations.

       use_bayes_rules ( 0 | 1 )          (default: 1)
           Whether to use rules using the naive-Bayesian-style classifier built into
           SpamAssassin.  This allows you to disable the rules while leaving auto and manual
           learning enabled.

       bayes_auto_learn ( 0 | 1 )      (default: 1)
           Whether SpamAssassin should automatically feed high-scoring mails (or low-scoring
           mails, for non-spam) into its learning systems.  The only learning system supported
           currently is a naive-Bayesian-style classifier.

           See the documentation for the "Mail::SpamAssassin::Plugin::AutoLearnThreshold" plugin
           module for details on how Bayes auto-learning is implemented by default.

       bayes_token_sources  (default: header visible invisible uri)
           Controls which sources in a mail message can contribute tokens (e.g. words, phrases,
           etc.) to a Bayes classifier. The argument is a space-separated list of keywords:
           header, visible, invisible, uri, mimepart), each of which may be prefixed by a no to
           indicate its exclusion. Additionally two reserved keywords are allowed: all and none
           (or: noall). The list of keywords is processed sequentially: a keyword all adds all
           available keywords to a set being built, a none or noall clears the set, other non-
           negated keywords are added to the set, and negated keywords are removed from the set.
           Keywords are case-insensitive.

           The default set is: header visible invisible uri, which is equivalent for example to:
           All NoMIMEpart. The reason why mimepart is not currently in a default set is that it
           is a newer source (introduced with SpamAssassin version 3.4.1) and not much experience
           has yet been gathered regarding its usefulness.

           See also option "bayes_ignore_header" for a fine-grained control on individual header
           fields under the umbrella of a more general keyword header here.

           Keywords imply the following data sources:

           header - tokens collected from a message header section
           visible - words from visible text (plain or HTML) in a message body
           invisible - hidden/invisible text in HTML parts of a message body
           uri - URIs collected from a message body
           mimepart - digests (hashes) of all MIME parts (textual or non-textual) of a message,
           computed after Base64 and quoted-printable decoding, suffixed by their Content-Type
           all - adds all the above keywords to the set being assembled
           none or noall - removes all keywords from the set

           The "bayes_token_sources" directive may appear multiple times, its keywords are
           interpreted sequentially, adding or removing items from the final set as they appear
           in their order in "bayes_token_sources" directive(s).

       bayes_ignore_header header_name
           If you receive mail filtered by upstream mail systems, like a spam-filtering ISP or
           mailing list, and that service adds new headers (as most of them do), these headers
           may provide inappropriate cues to the Bayesian classifier, allowing it to take a
           "short cut". To avoid this, list the headers using this setting.  Example:

                   bayes_ignore_header X-Upstream-Spamfilter
                   bayes_ignore_header X-Upstream-SomethingElse

       bayes_ignore_from user@example.com
           Bayesian classification and autolearning will not be performed on mail from the listed
           addresses.  Program "sa-learn" will also ignore the listed addresses if it is invoked
           using the "--use-ignores" option.  One or more addresses can be listed, see
           "whitelist_from".

           Spam messages from certain senders may contain many words that frequently occur in
           ham.  For example, one might read messages from a preferred bookstore but also get
           unwanted spam messages from other bookstores.  If the unwanted messages are learned as
           spam then any messages discussing books, including the preferred bookstore and
           antiquarian messages would be in danger of being marked as spam.  The addresses of the
           annoying bookstores would be listed.  (Assuming they were halfway legitimate and
           didn't send you mail through myriad affiliates.)

           Those who have pieces of spam in legitimate messages or otherwise receive ham messages
           containing potentially spammy words might fear that some spam messages might be in
           danger of being marked as ham.  The addresses of the spam mailing lists,
           correspondents, etc.  would be listed.

       bayes_ignore_to user@example.com
           Bayesian classification and autolearning will not be performed on mail to the listed
           addresses.  See "bayes_ignore_from" for details.

       bayes_min_ham_num             (Default: 200)
       bayes_min_spam_num       (Default: 200)
           To be accurate, the Bayes system does not activate until a certain number of ham (non-
           spam) and spam have been learned.  The default is 200 of each ham and spam, but you
           can tune these up or down with these two settings.

       bayes_learn_during_report         (Default: 1)
           The Bayes system will, by default, learn any reported messages ("spamassassin -r") as
           spam.  If you do not want this to happen, set this option to 0.

       bayes_sql_override_username
           Used by BayesStore::SQL storage implementation.

           If this options is set the BayesStore::SQL module will override the set username with
           the value given.  This could be useful for implementing global or group bayes
           databases.

       bayes_use_hapaxes        (default: 1)
           Should the Bayesian classifier use hapaxes (words/tokens that occur only once) when
           classifying?  This produces significantly better hit-rates.

       bayes_journal_max_size        (default: 102400)
           SpamAssassin will opportunistically sync the journal and the database.  It will do so
           once a day, but will sync more often if the journal file size goes above this setting,
           in bytes.  If set to 0, opportunistic syncing will not occur.

       bayes_expiry_max_db_size      (default: 150000)
           What should be the maximum size of the Bayes tokens database?  When expiry occurs, the
           Bayes system will keep either 75% of the maximum value, or 100,000 tokens, whichever
           has a larger value.  150,000 tokens is roughly equivalent to a 8Mb database file.

       bayes_auto_expire             (default: 1)
           If enabled, the Bayes system will try to automatically expire old tokens from the
           database.  Auto-expiry occurs when the number of tokens in the database surpasses the
           bayes_expiry_max_db_size value. If a bayes datastore backend does not implement
           individual key/value expirations, the setting is silently ignored.

       bayes_token_ttl               (default: 3w, i.e. 3 weeks)
           Time-to-live / expiration time in seconds for tokens kept in a Bayes database.  A
           numeric value is optionally suffixed by a time unit (s, m, h, d, w, indicating seconds
           (default), minutes, hours, days, weeks).

           If bayes_auto_expire is true and a Bayes datastore backend supports it (currently only
           Redis), this setting controls deletion of expired tokens from a bayes database. The
           value is observed on a best-effort basis, exact timing promises are not necessarily
           kept. If a bayes datastore backend does not implement individual key/value
           expirations, the setting is silently ignored.

       bayes_seen_ttl                (default: 8d, i.e. 8 days)
           Time-to-live / expiration time in seconds for 'seen' entries (i.e. mail message
           digests with their status) kept in a Bayes database.  A numeric value is optionally
           suffixed by a time unit (s, m, h, d, w, indicating seconds (default), minutes, hours,
           days, weeks).

           If bayes_auto_expire is true and a Bayes datastore backend supports it (currently only
           Redis), this setting controls deletion of expired 'seen' entries from a bayes
           database. The value is observed on a best-effort basis, exact timing promises are not
           necessarily kept. If a bayes datastore backend does not implement individual key/value
           expirations, the setting is silently ignored.

       bayes_learn_to_journal   (default: 0)
           If this option is set, whenever SpamAssassin does Bayes learning, it will put the
           information into the journal instead of directly into the database.  This lowers
           contention for locking the database to execute an update, but will also cause more
           access to the journal and cause a delay before the updates are actually committed to
           the Bayes database.

   MISCELLANEOUS OPTIONS
       time_limit n   (default: 300)
           Specifies a limit on elapsed time in seconds that SpamAssassin is allowed to spend
           before providing a result. The value may be fractional and must not be negative, zero
           is interpreted as unlimited. The default is 300 seconds for consistency with the spamd
           default setting of --timeout-child .

           This is a best-effort advisory setting, processing will not be abruptly aborted at an
           arbitrary point in processing when the time limit is exceeded, but only on reaching
           one of locations in the program flow equipped with a time test. Currently equipped
           with the test are the main checking loop, asynchronous DNS lookups, plugins which are
           calling external programs.  Rule evaluation is guarded by starting a timer (alarm) on
           each set of compiled rules.

           When a message is passed to Mail::SpamAssassin::parse, a deadline time is established
           as a sum of current time and the "time_limit" setting.

           This deadline may also be specified by a caller through an option 'master_deadline' in
           $suppl_attrib on a call to parse(), possibly providing a more accurate deadline taking
           into account past and expected future processing of a message in a mail filtering
           setup. If both the config option as well as a 'master_deadline' option in a call are
           provided, the shorter time limit of the two is used (since version 3.3.2).  Note that
           spamd (and possibly third-party callers of SpamAssassin) will supply the
           'master_deadline' option in a call based on its --timeout-child option (or
           equivalent), unlike the command line "spamassassin", which has no such command line
           option.

           When a time limit is exceeded, most of the remaining tests will be skipped, as well as
           auto-learning. Whatever tests fired so far will determine the final score. The
           behaviour is similar to short-circuiting with attribute 'on', as implemented by a
           Shortcircuit plugin. A synthetic hit on a rule named TIME_LIMIT_EXCEEDED with a near-
           zero default score is generated, so that the report will reflect the event. A score
           for TIME_LIMIT_EXCEEDED may be provided explicitly in a configuration file, for
           example to achieve whitelisting or blacklisting effect for messages with long
           processing times.

           The "time_limit" option is a useful protection against excessive processing time on
           certain degenerate or unusually long or complex mail messages, as well as against some
           DoS attacks. It is also needed in time-critical pre-queue filtering setups (e.g.
           milter, proxy, integration with MTA), where message processing must finish before a
           SMTP client times out.  RFC 5321 prescribes in section 4.5.3.2.6 the 'DATA
           Termination' time limit of 10 minutes, although it is not unusual to see some SMTP
           clients abort sooner on waiting for a response. A sensible "time_limit" for a pre-
           queue filtering setup is maybe 50 seconds, assuming that clients are willing to wait
           at least a minute.

       lock_method type
           Select the file-locking method used to protect database files on-disk. By default,
           SpamAssassin uses an NFS-safe locking method on UNIX; however, if you are sure that
           the database files you'll be using for Bayes and AWL storage will never be accessed
           over NFS, a non-NFS-safe locking system can be selected.

           This will be quite a bit faster, but may risk file corruption if the files are ever
           accessed by multiple clients at once, and one or more of them is accessing them
           through an NFS filesystem.

           Note that different platforms require different locking systems.

           The supported locking systems for "type" are as follows:

           nfssafe - an NFS-safe locking system
           flock - simple UNIX "flock()" locking
           win32 - Win32 locking using "sysopen (..., O_CREAT|O_EXCL)".

           nfssafe and flock are only available on UNIX, and win32 is only available on Windows.
           By default, SpamAssassin will choose either nfssafe or win32 depending on the platform
           in use.

       fold_headers ( 0 | 1 )        (default: 1)
           By default, headers added by SpamAssassin will be whitespace folded.  In other words,
           they will be broken up into multiple lines instead of one very long one and each
           continuation line will have a tabulator prepended to mark it as a continuation of the
           preceding one.

           The automatic wrapping can be disabled here.  Note that this can generate very long
           lines.  RFC 2822 required that header lines do not exceed 998 characters (not counting
           the final CRLF).

       report_safe_copy_headers header_name ...
           If using "report_safe", a few of the headers from the original message are copied into
           the wrapper header (From, To, Cc, Subject, Date, etc.)  If you want to have other
           headers copied as well, you can add them using this option.  You can specify multiple
           headers on the same line, separated by spaces, or you can just use multiple lines.

       envelope_sender_header Name-Of-Header
           SpamAssassin will attempt to discover the address used in the 'MAIL FROM:' phase of
           the SMTP transaction that delivered this message, if this data has been made available
           by the SMTP server.  This is used in the "EnvelopeFrom" pseudo-header, and for various
           rules such as SPF checking.

           By default, various MTAs will use different headers, such as the following:

               X-Envelope-From
               Envelope-Sender
               X-Sender
               Return-Path

           SpamAssassin will attempt to use these, if some heuristics (such as the header
           placement in the message, or the absence of fetchmail signatures) appear to indicate
           that they are safe to use.  However, it may choose the wrong headers in some
           mailserver configurations.  (More discussion of this can be found in bug 2142 and bug
           4747 in the SpamAssassin BugZilla.)

           To avoid this heuristic failure, the "envelope_sender_header" setting may be helpful.
           Name the header that your MTA or MDA adds to messages containing the address used at
           the MAIL FROM step of the SMTP transaction.

           If the header in question contains "<" or ">" characters at the start and end of the
           email address in the right-hand side, as in the SMTP transaction, these will be
           stripped.

           If the header is not found in a message, or if it's value does not contain an "@"
           sign, SpamAssassin will issue a warning in the logs and fall back to its default
           heuristics.

           (Note for MTA developers: we would prefer if the use of a single header be avoided in
           future, since that precludes 'downstream' spam scanning.
           "http://wiki.apache.org/spamassassin/EnvelopeSenderInReceived" details a better
           proposal, storing the envelope sender at each hop in the "Received" header.)

           example:

               envelope_sender_header X-SA-Exim-Mail-From

       describe SYMBOLIC_TEST_NAME description ...
           Used to describe a test.  This text is shown to users in the detailed report.

           Note that test names which begin with '__' are reserved for meta-match sub-rules, and
           are not scored or listed in the 'tests hit' reports.

           Also note that by convention, rule descriptions should be limited in length to no more
           than 50 characters.

       report_charset CHARSET        (default: unset)
           Set the MIME Content-Type charset used for the text/plain report which is attached to
           spam mail messages.

       report ...some text for a report...
           Set the report template which is attached to spam mail messages.  See the
           "10_default_prefs.cf" configuration file in "/usr/share/spamassassin" for an example.

           If you change this, try to keep it under 78 columns. Each "report" line appends to the
           existing template, so use "clear_report_template" to restart.

           Tags can be included as explained above.

       clear_report_template
           Clear the report template.

       report_contact ...text of contact address...
           Set what _CONTACTADDRESS_ is replaced with in the above report text.  By default, this
           is 'the administrator of that system', since the hostname of the system the scanner is
           running on is also included.

       report_hostname ...hostname to use...
           Set what _HOSTNAME_ is replaced with in the above report text.  By default, this is
           determined dynamically as whatever the host running SpamAssassin calls itself.

       unsafe_report ...some text for a report...
           Set the report template which is attached to spam mail messages which contain a
           non-text/plain part.  See the "10_default_prefs.cf" configuration file in
           "/usr/share/spamassassin" for an example.

           Each "unsafe-report" line appends to the existing template, so use
           "clear_unsafe_report_template" to restart.

           Tags can be used in this template (see above for details).

       clear_unsafe_report_template
           Clear the unsafe_report template.

       mbox_format_from_regex
           Set a specific regular expression to be used for mbox file From separators.

           For example, this setting will allow sa-learn to process emails stored in a kmail 2
           mbox:

           mbox_format_from_regex /^From \S+  ?[[:upper:]][[:lower:]]{2}(?:, \d\d
           [[:upper:]][[:lower:]]{2} \d{4} [0-2]\d:\d\d:\d\d [+-]\d{4}| [[:upper:]][[:lower:]]{2}
           [ 1-3]\d [ 0-2]\d:\d\d:\d\d \d{4})/

       parse_dkim_uris ( 0 | 1 ) (default: 1)
           If this option is set to 1 and the message contains DKIM headers, the headers will be
           parsed for URIs to process alongside URIs found in the body with some rules and
           modules (ex. URIDNSBL)

RULE DEFINITIONS AND PRIVILEGED SETTINGS

       These settings differ from the ones above, in that they are considered 'privileged'.  Only
       users running "spamassassin" from their procmailrc's or forward files, or sysadmins
       editing a file in "/etc/spamassassin", can use them.   "spamd" users cannot use them in
       their "user_prefs" files, for security and efficiency reasons, unless "allow_user_rules"
       is enabled (and then, they may only add rules from below).

       allow_user_rules ( 0 | 1 )         (default: 0)
           This setting allows users to create rules (and only rules) in their "user_prefs" files
           for use with "spamd". It defaults to off, because this could be a severe security
           hole. It may be possible for users to gain root level access if "spamd" is run as
           root. It is NOT a good idea, unless you have some other way of ensuring that users'
           tests are safe. Don't use this unless you are certain you know what you are doing.
           Furthermore, this option causes spamassassin to recompile all the tests each time it
           processes a message for a user with a rule in his/her "user_prefs" file, which could
           have a significant effect on server load. It is not recommended.

           Note that it is not currently possible to use "allow_user_rules" to modify an existing
           system rule from a "user_prefs" file with "spamd".

       redirector_pattern  /pattern/modifiers
           A regex pattern that matches both the redirector site portion, and the target site
           portion of a URI.

           Note: The target URI portion must be surrounded in parentheses and
                 no other part of the pattern may create a backreference.

           Example: http://chkpt.zdnet.com/chkpt/whatever/spammer.domain/yo/dude

             redirector_pattern    /^https?:\/\/(?:opt\.)?chkpt\.zdnet\.com\/chkpt\/\w+\/(.*)$/i

       header SYMBOLIC_TEST_NAME header op /pattern/modifiers [if-unset: STRING]
           Define a test.  "SYMBOLIC_TEST_NAME" is a symbolic test name, such as
           'FROM_ENDS_IN_NUMS'.  "header" is the name of a mail header field, such as 'Subject',
           'To', 'From', etc.  Header field names are matched case-insensitively (conforming to
           RFC 5322 section 1.2.2), except for all-capitals metaheader fields such as ALL,
           MESSAGEID, ALL-TRUSTED.

           Appending a modifier ":raw" to a header field name will inhibit decoding of quoted-
           printable or base-64 encoded strings, and will preserve all whitespace inside the
           header string.  The ":raw" may also be applied to pseudo-headers e.g. "ALL:raw" will
           return a pristine (unmodified) header section.

           Appending a modifier ":addr" to a header field name will cause everything except the
           first email address to be removed from the header field.  It is mainly applicable to
           header fields 'From', 'Sender', 'To', 'Cc' along with their 'Resent-*' counterparts,
           and the 'Return-Path'.

           Appending a modifier ":name" to a header field name will cause everything except the
           first display name to be removed from the header field. It is mainly applicable to
           header fields containing a single mail address: 'From', 'Sender', along with their
           'Resent-From' and 'Resent-Sender' counterparts.

           It is syntactically permitted to append more than one modifier to a header field name,
           although currently most combinations achieve no additional effect, for example
           "From:addr:raw" or "From:raw:addr" is currently the same as "From:addr" .

           For example, appending ":addr" to a header name will result in example@foo in all of
           the following cases:

           example@foo
           example@foo (Foo Blah)
           example@foo, example@bar
           display: example@foo (Foo Blah), example@bar ;
           Foo Blah <example@foo>
           "Foo Blah" <example@foo>
           "'Foo Blah'" <example@foo>

           For example, appending ":name" to a header name will result in "Foo Blah" (without
           quotes) in all of the following cases:

           example@foo (Foo Blah)
           example@foo (Foo Blah), example@bar
           display: example@foo (Foo Blah), example@bar ;
           Foo Blah <example@foo>
           "Foo Blah" <example@foo>
           "'Foo Blah'" <example@foo>

           There are several special pseudo-headers that can be specified:

           "ALL" can be used to mean the text of all the message's headers. Note that all
           whitespace inside the headers, at line folds, is currently compressed into a single
           space (' ') character. To obtain a pristine (unmodified) header section, use "ALL:raw"
           - the :raw modifier is documented above. Also similar that return headers added by
           specific relays: ALL-TRUSTED, ALL-INTERNAL, ALL-UNTRUSTED, ALL-EXTERNAL.
           "ToCc" can be used to mean the contents of both the 'To' and 'Cc' headers.
           "EnvelopeFrom" is the address used in the 'MAIL FROM:' phase of the SMTP transaction
           that delivered this message, if this data has been made available by the SMTP server.
           See "envelope_sender_header" for more information on how to set this.
           "MESSAGEID" is a symbol meaning all Message-Id's found in the message; some mailing
           list software moves the real 'Message-Id' to 'Resent-Message-Id' or to 'X-Message-Id',
           then uses its own one in the 'Message-Id' header. The value returned for this symbol
           is the text from all 3 headers, separated by newlines.
           "X-Spam-Relays-Untrusted", "X-Spam-Relays-Trusted", "X-Spam-Relays-Internal" and
           "X-Spam-Relays-External" represent a portable, pre-parsed representation of the
           message's network path, as recorded in the Received headers, divided into 'trusted' vs
           'untrusted' and 'internal' vs 'external' sets.  See
           "http://wiki.apache.org/spamassassin/TrustedRelays" for more details.

           "op" is either "=~" (contains regular expression) or "!~" (does not contain regular
           expression), and "pattern" is a valid Perl regular expression, with "modifiers" as
           regexp modifiers in the usual style.   Note that multi-line rules are not supported,
           even if you use "x" as a modifier.  Also note that the "#" character must be escaped
           ("\#") or else it will be considered to be the start of a comment and not part of the
           regexp.

           If the header specified matches multiple headers, their text will be concatenated with
           embedded \n's. Therefore you may wish to use "/m" if you use "^" or "$" in your
           regular expression.

           If the "[if-unset: STRING]" tag is present, then "STRING" will be used if the header
           is not found in the mail message.

           Test names must not start with a number, and must contain only alphanumerics and
           underscores.  It is suggested that lower-case characters not be used, and names have a
           length of no more than 22 characters, as an informal convention.  Dashes are not
           allowed.

           Note that test names which begin with '__' are reserved for meta-match sub-rules, and
           are not scored or listed in the 'tests hit' reports.  Test names which begin with 'T_'
           are reserved for tests which are undergoing QA, and these are given a very low score.

           If you add or modify a test, please be sure to run a sanity check afterwards by
           running "spamassassin --lint".  This will avoid confusing error messages, or other
           tests being skipped as a side-effect.

       header SYMBOLIC_TEST_NAME exists:header_field_name
           Define a header field existence test.  "header_field_name" is the name of a header
           field to test for existence.  Not to be confused with a test for a nonempty header
           field body, which can be implemented by a "header SYMBOLIC_TEST_NAME header =~ /\S/"
           rule as described above.

       header SYMBOLIC_TEST_NAME eval:name_of_eval_method([arguments])
           Define a header eval test.  "name_of_eval_method" is the name of a method registered
           by a "Mail::SpamAssassin::Plugin" object.  "arguments" are optional arguments to the
           function call.

       header SYMBOLIC_TEST_NAME eval:check_rbl('set', 'zone' [, 'sub-test'])
           Check a DNSBL (a DNS blacklist or whitelist).  This will retrieve Received: headers
           from the message, extract the IP addresses, select which ones are 'untrusted' based on
           the "trusted_networks" logic, and query that DNSBL zone.  There's a few things to
           note:

           duplicated or private IPs
               Duplicated IPs are only queried once and reserved IPs are not queried.  Private
               IPs are those listed in <https://www.iana.org/assignments/ipv4-address-space>,
               <http://duxcw.com/faq/network/privip.htm>,
               <http://duxcw.com/faq/network/autoip.htm>, or
               <https://tools.ietf.org/html/rfc5735> as private.

           the 'set' argument
               This is used as a 'zone ID'.  If you want to look up a multiple-meaning zone like
               SORBS, you can then query the results from that zone using it; but all
               check_rbl_sub() calls must use that zone ID.

               Also, if more than one IP address gets a DNSBL hit for a particular rule, it does
               not affect the score because rules only trigger once per message.

           the 'zone' argument
               This is the root zone of the DNSBL.

               The domain name is considered to be a fully qualified domain name (i.e. not
               subject to DNS resolver's search or default domain options).  No trailing period
               is needed, and will be removed if specified.

           the 'sub-test' argument
               This optional argument behaves the same as the sub-test argument in
               "check_rbl_sub()" below.

           selecting all IPs except for the originating one
               This is accomplished by placing '-notfirsthop' at the end of the set name.  This
               is useful for querying against DNS lists which list dialup IP addresses; the first
               hop may be a dialup, but as long as there is at least one more hop, via their
               outgoing SMTP server, that's legitimate, and so should not gain points.  If there
               is only one hop, that will be queried anyway, as it should be relaying via its
               outgoing SMTP server instead of sending directly to your MX (mail exchange).

           selecting IPs by whether they are trusted
               When checking a 'nice' DNSBL (a DNS whitelist), you cannot trust the IP addresses
               in Received headers that were not added by trusted relays.  To test the first IP
               address that can be trusted, place '-firsttrusted' at the end of the set name.
               That should test the IP address of the relay that connected to the most remote
               trusted relay.

               Note that this requires that SpamAssassin know which relays are trusted.  For
               simple cases, SpamAssassin can make a good estimate.  For complex cases, you may
               get better results by setting "trusted_networks" manually.

               In addition, you can test all untrusted IP addresses by placing '-untrusted' at
               the end of the set name.   Important note -- this does NOT include the IP address
               from the most recent 'untrusted line', as used in '-firsttrusted' above.  That's
               because we're talking about the trustworthiness of the IP address data, not the
               source header line, here; and in the case of the most recent header (the
               'firsttrusted'), that data can be trusted.  See the Wiki page at
               "http://wiki.apache.org/spamassassin/TrustedRelays" for more information on this.

           Selecting just the last external IP
               By using '-lastexternal' at the end of the set name, you can select only the
               external host that connected to your internal network, or at least the last
               external host with a public IP.

       header SYMBOLIC_TEST_NAME eval:check_rbl_txt('set', 'zone')
           Same as check_rbl(), except querying using IN TXT instead of IN A records.  If the
           zone supports it, it will result in a line of text describing why the IP is listed,
           typically a hyperlink to a database entry.

       header SYMBOLIC_TEST_NAME eval:check_rbl_sub('set', 'sub-test')
           Create a sub-test for 'set'.  If you want to look up a multi-meaning zone like
           relays.osirusoft.com, you can then query the results from that zone using the zone ID
           from the original query.  The sub-test may either be an IPv4 dotted address for RBLs
           that return multiple A records, or a non-negative decimal number to specify a bitmask
           for RBLs that return a single A record containing a bitmask of results, or a regular
           expression.

           Note: the set name must be exactly the same for as the main query rule, including
           selections like '-notfirsthop' appearing at the end of the set name.

       body SYMBOLIC_TEST_NAME /pattern/modifiers
           Define a body pattern test.  "pattern" is a Perl regular expression.  Note: as per the
           header tests, "#" must be escaped ("\#") or else it is considered the beginning of a
           comment.

           The 'body' in this case is the textual parts of the message body; any non-text MIME
           parts are stripped, and the message decoded from Quoted-Printable or Base-64-encoded
           format if necessary.  Parts declared as text/html will be rendered from HTML to text.

           All body paragraphs (double-newline-separated blocks text) are turned into a line
           breaks removed, whitespace normalized single line.  Any lines longer than 2kB are
           split into shorter separate lines (from a boundary when possible), this may
           unexpectedly prevent pattern from matching.  Patterns are matched independently
           against each of these lines.

           Note that by default the message Subject header is considered part of the body and
           becomes the first line when running the rules. If you don't want to match Subject
           along with body text, use "tflags RULENAME nosubject".

       body SYMBOLIC_TEST_NAME eval:name_of_eval_method([args])
           Define a body eval test.  See above.

       uri SYMBOLIC_TEST_NAME /pattern/modifiers
           Define a uri pattern test.  "pattern" is a Perl regular expression.  Note: as per the
           header tests, "#" must be escaped ("\#") or else it is considered the beginning of a
           comment.

           The 'uri' in this case is a list of all the URIs in the body of the email, and the
           test will be run on each and every one of those URIs, adjusting the score if a match
           is found. Use this test instead of one of the body tests when you need to match a URI,
           as it is more accurately bound to the start/end points of the URI, and will also be
           faster.

       rawbody SYMBOLIC_TEST_NAME /pattern/modifiers
           Define a raw-body pattern test.  "pattern" is a Perl regular expression.  Note: as per
           the header tests, "#" must be escaped ("\#") or else it is considered the beginning of
           a comment.

           The 'raw body' of a message is the raw data inside all textual parts. The text will be
           decoded from base64 or quoted-printable encoding, but HTML tags and line breaks will
           still be present.  Multiline expressions will need to be used to match strings that
           are broken by line breaks.

           Note that the text is split into 2-4kB chunks (from a word boundary when possible),
           this may unexpectedly prevent pattern from matching.  Patterns are matched
           independently against each of these chunks.

       rawbody SYMBOLIC_TEST_NAME eval:name_of_eval_method([args])
           Define a raw-body eval test.  See above.

       full SYMBOLIC_TEST_NAME /pattern/modifiers
           Define a full message pattern test.  "pattern" is a Perl regular expression.  Note: as
           per the header tests, "#" must be escaped ("\#") or else it is considered the
           beginning of a comment.

           The full message is the pristine message headers plus the pristine message body,
           including all MIME data such as images, other attachments, MIME boundaries, etc.

       full SYMBOLIC_TEST_NAME eval:name_of_eval_method([args])
           Define a full message eval test.  See above.

       meta SYMBOLIC_TEST_NAME boolean expression
           Define a boolean expression test in terms of other tests that have been hit or not
           hit.  For example:

           meta META1        TEST1 && !(TEST2 || TEST3)

           Note that English language operators ("and", "or") will be treated as rule names, and
           that there is no "XOR" operator.

       meta SYMBOLIC_TEST_NAME boolean arithmetic expression
           Can also define an arithmetic expression in terms of other tests, with an unhit test
           having the value "0" and a hit test having a nonzero value.  The value of a hit meta
           test is that of its arithmetic expression.  The value of a hit eval test is that
           returned by its method.  The value of a hit header, body, rawbody, uri, or full test
           which has the "multiple" tflag is the number of times the test hit.  The value of any
           other type of hit test is "1".

           For example:

           meta META2        (3 * TEST1 - 2 * TEST2) > 0

           Note that Perl builtins and functions, like "abs()", can't be used, and will be
           treated as rule names.

           If you want to define a meta-rule, but do not want its individual sub-rules to count
           towards the final score unless the entire meta-rule matches, give the sub-rules names
           that start with '__' (two underscores).  SpamAssassin will ignore these for scoring.

       meta SYMBOLIC_TEST_NAME ... rules_matching(RULEGLOB) ...
           Special function that will expand to list of matching rulenames.  Can be used anywhere
           in expressions.  Argument supports glob style rulename matching (* = anything, ? = one
           character).  Matching is case-sensitive.

           For example, this will hit if at least two __FOO_* rule hits:

            body __FOO_1  /xxx/
            body __FOO_2  /yyy/
            body __FOO_3  /zzz/
            meta FOO_META  rules_matching(__FOO_*) >= 2

           Which would be the same as:

            meta FOO_META  (__FOO_1 + __FOO_2 + __FOO_3) >= 2

       reuse SYMBOLIC_TEST_NAME [ OLD_SYMBOLIC_TEST_NAME_1 ... ]
           Defines the name of a test that should be "reused" during the scoring process. If a
           message has an X-Spam-Status header that shows a hit for this rule or any of the old
           rule names given, a hit will be added for this rule when mass-check --reuse is used.
           Examples:

           "reuse SPF_PASS"

           "reuse MY_NET_RULE_V2 MY_NET_RULE_V1"

           The actual logic for reuse tests is done by Mail::SpamAssassin::Plugin::Reuse.

       tflags SYMBOLIC_TEST_NAME flags
           Used to set flags on a test. Parameter is a space-separated list of flag names or flag
           name = value pairs.  These flags are used in the score-determination back end system
           for details of the test's behaviour.  Please see "bayes_auto_learn" for more
           information about tflag interaction with those systems. The following flags can be
           set:

           net The test is a network test, and will not be run in the mass checking system or if
               -L is used, therefore its score should not be modified.

           nice
               The test is intended to compensate for common false positives, and should be
               assigned a negative score.

           userconf
               The test requires user configuration before it can be used (like language-specific
               tests).

           learn
               The test requires training before it can be used.

           noautolearn
               The test will explicitly be ignored when calculating the score for learning
               systems.

           autolearn_force
               The test will be subject to less stringent autolearn thresholds.

               Normally, SpamAssassin will require 3 points from the header and 3 points from the
               body to be auto-learned as spam. This option keeps the threshold at 6 points total
               but changes it to have no regard to the source of the points.

           noawl
               This flag is specific when using AWL plugin.

               Normally, AWL plugin normalizes scores via auto-whitelist. In some scenarios it
               works against the system administrator when trying to add some rules to correct
               miss-classified email. When AWL plugin searches the email and finds the noawl flag
               it will exit without normalizing the score nor storing the value in db.

           multiple
               The test will be evaluated multiple times, for use with meta rules.  Only affects
               header, body, rawbody, uri, and full tests.

           maxhits=N
               If multiple is specified, limit the number of hits found to N.  If the rule is
               used in a meta that counts the hits (e.g. __RULENAME > 5), this is a way to avoid
               wasted extra work (use "tflags multiple maxhits=6").

               For example:

                 uri      __KAM_COUNT_URIS /^./
                 tflags   __KAM_COUNT_URIS multiple maxhits=16
                 describe __KAM_COUNT_URIS A multiple match used to count URIs in a message

                 meta __KAM_HAS_0_URIS (__KAM_COUNT_URIS == 0)
                 meta __KAM_HAS_1_URIS (__KAM_COUNT_URIS >= 1)
                 meta __KAM_HAS_2_URIS (__KAM_COUNT_URIS >= 2)
                 meta __KAM_HAS_3_URIS (__KAM_COUNT_URIS >= 3)
                 meta __KAM_HAS_4_URIS (__KAM_COUNT_URIS >= 4)
                 meta __KAM_HAS_5_URIS (__KAM_COUNT_URIS >= 5)
                 meta __KAM_HAS_10_URIS (__KAM_COUNT_URIS >= 10)
                 meta __KAM_HAS_15_URIS (__KAM_COUNT_URIS >= 15)

           nosubject
               Used only for body rules.  If specified, Subject header will not be a part of the
               matched body text.  See body for more info.

           ips_only
               This flag is specific to rules invoking an URIDNSBL plugin, it is documented
               there.

           domains_only
               This flag is specific to rules invoking an URIDNSBL plugin, it is documented
               there.

           ns  This flag is specific to rules invoking an URIDNSBL plugin, it is documented
               there.

           a   This flag is specific to rules invoking an URIDNSBL plugin, it is documented
               there.

       priority SYMBOLIC_TEST_NAME n
           Assign a specific priority to a test.  All tests, except for DNS and Meta tests, are
           run in increasing priority value order (negative priority values are run before
           positive priority values). The default test priority is 0 (zero).

           The values <-99999999999999> and <-99999999999998> have a special meaning internally,
           and should not be used.

ADMINISTRATOR SETTINGS

       These settings differ from the ones above, in that they are considered 'more privileged'
       -- even more than the ones in the PRIVILEGED SETTINGS section.  No matter what
       "allow_user_rules" is set to, these can never be set from a user's "user_prefs" file when
       spamc/spamd is being used.  However, all settings can be used by local programs run
       directly by the user.

       version_tag string
           This tag is appended to the SA version in the X-Spam-Status header. You should include
           it when you modify your ruleset, especially if you plan to distribute it.  A good
           choice for string is your last name or your initials followed by a number which you
           increase with each change.

           The version_tag will be lowercased, and any non-alphanumeric or period character will
           be replaced by an underscore.

           e.g.

             version_tag myrules1    # version=2.41-myrules1

       test SYMBOLIC_TEST_NAME (ok|fail) Some string to test against
           Define a regression testing string. You can have more than one regression test string
           per symbolic test name. Simply specify a string that you wish the test to match.

           These tests are only run as part of the test suite - they should not affect the
           general running of SpamAssassin.

       rbl_timeout t [t_min] [zone]       (default: 15 3)
           All DNS queries are made at the beginning of a check and we try to read the results at
           the end.  This value specifies the maximum period of time (in seconds) to wait for a
           DNS query.  If most of the DNS queries have succeeded for a particular message, then
           SpamAssassin will not wait for the full period to avoid wasting time on unresponsive
           server(s), but will shrink the timeout according to a percentage of queries already
           completed.  As the number of queries remaining approaches 0, the timeout value will
           gradually approach a t_min value, which is an optional second parameter and defaults
           to 0.2 * t.  If t is smaller than t_min, the initial timeout is set to t_min.  Here is
           a chart of queries remaining versus the timeout in seconds, for the default 15 second
           / 3 second timeout setting:

             queries left  100%  90%  80%  70%  60%  50%  40%  30%  20%  10%   0%
             timeout        15   14.9 14.5 13.9 13.1 12.0 10.7  9.1  7.3  5.3  3

           For example, if 20 queries are made at the beginning of a message check and 16 queries
           have returned (leaving 20%), the remaining 4 queries should finish within 7.3 seconds
           since their query started or they will be timed out.  Note that timed out queries are
           only aborted when there is nothing else left for SpamAssassin to do - long evaluation
           of other rules may grant queries additional time.

           If a parameter 'zone' is specified (it must end with a letter, which distinguishes it
           from other numeric parametrs), then the setting only applies to DNS queries against
           the specified DNS domain (host, domain or RBL (sub)zone).  Matching is case-
           insensitive, the actual domain may be a subdomain of the specified zone.

       util_rb_tld tld1 tld2 ...
           This option maintains list of valid TLDs in the RegistryBoundaries code.  TLDs include
           things like com, net, org, etc.

       util_rb_2tld 2tld-1.tld 2tld-2.tld ...
           This option maintains list of valid 2nd-level TLDs in the RegistryBoundaries code.
           2TLDs include things like co.uk, fed.us, etc.

       util_rb_3tld 3tld1.some.tld 3tld2.other.tld ...
           This option maintains list of valid 3rd-level TLDs in the RegistryBoundaries code.
           3TLDs include things like demon.co.uk, plc.co.im, etc.

       clear_util_rb
           Empty internal list of valid TLDs (including 2nd and 3rd level) which
           RegistryBoundaries code uses.  Only useful if you want to override the standard lists
           supplied by sa-update.

       bayes_path /path/filename     (default: ~/.spamassassin/bayes)
           This is the directory and filename for Bayes databases.  Several databases will be
           created, with this as the base directory and filename, with "_toks", "_seen", etc.
           appended to the base.  The default setting results in files called
           "~/.spamassassin/bayes_seen", "~/.spamassassin/bayes_toks", etc.

           By default, each user has their own in their "~/.spamassassin" directory with mode
           0700/0600.  For system-wide SpamAssassin use, you may want to reduce disk space usage
           by sharing this across all users.  However, Bayes appears to be more effective with
           individual user databases.

       bayes_file_mode          (default: 0700)
           The file mode bits used for the Bayesian filtering database files.

           Make sure you specify this using the 'x' mode bits set, as it may also be used to
           create directories.  However, if a file is created, the resulting file will not have
           any execute bits set (the umask is set to 111). The argument is a string of octal
           digits, it is converted to a numeric value internally.

       bayes_store_module Name::Of::BayesStore::Module
           If this option is set, the module given will be used as an alternate to the default
           bayes storage mechanism.  It must conform to the published storage specification (see
           Mail::SpamAssassin::BayesStore). For example, set this to
           Mail::SpamAssassin::BayesStore::SQL to use the generic SQL storage module.

       bayes_sql_dsn DBI::databasetype:databasename:hostname:port
           Used for BayesStore::SQL storage implementation.

           This option give the connect string used to connect to the SQL based Bayes storage.

       bayes_sql_username
           Used by BayesStore::SQL storage implementation.

           This option gives the username used by the above DSN.

       bayes_sql_password
           Used by BayesStore::SQL storage implementation.

           This option gives the password used by the above DSN.

       bayes_sql_username_authorized ( 0 | 1 )  (default: 0)
           Whether to call the services_authorized_for_username plugin hook in BayesSQL.  If the
           hook does not determine that the user is allowed to use bayes or is invalid then the
           database will not be initialized.

           NOTE: By default the user is considered invalid until a plugin returns a true value.
           If you enable this, but do not have a proper plugin loaded, all users will turn up as
           invalid.

           The username passed into the plugin can be affected by the bayes_sql_override_username
           config option.

       user_scores_dsn DBI:databasetype:databasename:hostname:port
           If you load user scores from an SQL database, this will set the DSN used to connect.
           Example: "DBI:mysql:spamassassin:localhost"

           If you load user scores from an LDAP directory, this will set the DSN used to connect.
           You have to write the DSN as an LDAP URL, the components being the host and port to
           connect to, the base DN for the search, the scope of the search (base, one or sub),
           the single attribute being the multivalued attribute used to hold the configuration
           data (space separated pairs of key and value, just as in a file) and finally the
           filter being the expression used to filter out the wanted username. Note that the
           filter expression is being used in a sprintf statement with the username as the only
           parameter, thus is can hold a single __USERNAME__ expression. This will be replaced
           with the username.

           Example: "ldap://localhost:389/dc=koehntopp,dc=de?saconfig?uid=__USERNAME__"

       user_scores_sql_username username
           The authorized username to connect to the above DSN.

       user_scores_sql_password password
           The password for the database username, for the above DSN.

       user_scores_sql_custom_query query
           This option gives you the ability to create a custom SQL query to retrieve user scores
           and preferences.  In order to work correctly your query should return two values, the
           preference name and value, in that order.  In addition, there are several "variables"
           that you can use as part of your query, these variables will be substituted for the
           current values right before the query is run.  The current allowed variables are:

           _TABLE_
               The name of the table where user scores and preferences are stored. Currently
               hardcoded to userpref, to change this value you need to create a new custom query
               with the new table name.

           _USERNAME_
               The current user's username.

           _MAILBOX_
               The portion before the @ as derived from the current user's username.

           _DOMAIN_
               The portion after the @ as derived from the current user's username, this value
               may be null.

           The query must be one continuous line in order to parse correctly.

           Here are several example queries, please note that these are broken up for easy
           reading, in your config it should be one continuous line.

           Current default query:
               "SELECT preference, value FROM _TABLE_ WHERE username = _USERNAME_ OR username =
               '@GLOBAL' ORDER BY username ASC"

           Use global and then domain level defaults:
               "SELECT preference, value FROM _TABLE_ WHERE username = _USERNAME_ OR username =
               '@GLOBAL' OR username = '@~'||_DOMAIN_ ORDER BY username ASC"

           Maybe global prefs should override user prefs:
               "SELECT preference, value FROM _TABLE_ WHERE username = _USERNAME_ OR username =
               '@GLOBAL' ORDER BY username DESC"

       user_scores_ldap_username
           This is the Bind DN used to connect to the LDAP server.  It defaults to the empty
           string (""), allowing anonymous binding to work.

           Example: "cn=master,dc=koehntopp,dc=de"

       user_scores_ldap_password
           This is the password used to connect to the LDAP server.  It defaults to the empty
           string ("").

       user_scores_fallback_to_global        (default: 1)
           Fall back to global scores and settings if userprefs can't be loaded from SQL or LDAP,
           instead of passing the message through unprocessed.

       loadplugin [Mail::SpamAssassin::Plugin::]ModuleName [/path/module.pm]
           Load a SpamAssassin plugin module.  The "ModuleName" is the perl module name, used to
           create the plugin object itself.

           Module naming is strict, name must only contain alphanumeric characters or
           underscores.  File must have .pm extension.

           "/path/module.pm" is the file to load, containing the module's perl code; if it's
           specified as a relative path, it's considered to be relative to the current
           configuration file.  If it is omitted, the module will be loaded using perl's search
           path (the @INC array).

           See "Mail::SpamAssassin::Plugin" for more details on writing plugins.

       tryplugin ModuleName [/path/module.pm]
           Same as "loadplugin", but silently ignored if the .pm file cannot be found in the
           filesystem.

       ignore_always_matching_regexps         (Default: 0)
           Ignore any rule which contains a regexp which always matches.  Currently only catches
           regexps which contain '||', or which begin or end with a '|'.  Also ignore rules with
           "some" combinatorial explosions.

PREPROCESSING OPTIONS

       include filename
           Include configuration lines from "filename".   Relative paths are considered relative
           to the current configuration file or user preferences file.

       if (boolean perl expression)
           Used to support conditional interpretation of the configuration file. Lines between
           this and a corresponding "else" or "endif" line will be ignored unless the expression
           evaluates as true (in the perl sense; that is, defined and non-0 and non-empty
           string).

           The conditional accepts a limited subset of perl for security -- just enough to
           perform basic arithmetic comparisons.  The following input is accepted:

           numbers, whitespace, arithmetic operations and grouping
               Namely these characters and ranges:

                 ( ) - + * / _ . , < = > ! ~ 0-9 whitespace

           version
               This will be replaced with the version number of the currently-running
               SpamAssassin engine.  Note: The version used is in the internal SpamAssassin
               version format which is "x.yyyzzz", where x is major version, y is minor version,
               and z is maintenance version.  So 3.0.0 is 3.000000, and 3.4.80 is 3.004080.

           perl_version
               (Introduced in 3.4.1)  This will be replaced with the version number of the
               currently-running perl engine.  Note: The version used is in the $] version format
               which is "x.yyyzzz", where x is major version, y is minor version, and z is
               maintenance version.  So 5.8.8 is 5.008008, and 5.10.0 is 5.010000. Use to protect
               rules that incorporate RE syntax elements introduced in later versions of perl,
               such as the "++" non-backtracking match introduced in perl 5.10. For example:

                 # Avoid lint error on older perl installs
                 # Check SA version first to avoid warnings on checking perl_version on older SA
                 if version > 3.004001 && perl_version >= 5.018000
                   body  INVALID_RE_SYNTAX_IN_PERL_BEFORE_5_18  /(?[ \p{Thai} & \p{Digit} ])/
                 endif

               Note that the above will still generate a warning on perl older than 5.10.0; to
               avoid that warning do this instead:

                 # Avoid lint error on older perl installs
                 if can(Mail::SpamAssassin::Conf::perl_min_version_5010000)
                   body  INVALID_RE_SYNTAX_IN_PERL_5_8  /\w++/
                 endif

               Warning: a can() test is only defined for perl 5.10.0!

           plugin(Name::Of::Plugin)
               This is a function call that returns 1 if the plugin named "Name::Of::Plugin" is
               loaded, or "undef" otherwise.

           has(Name::Of::Package::function_name)
               This is a function call that returns 1 if the perl package named
               "Name::Of::Package" includes a function called "function_name", or "undef"
               otherwise.  Note that packages can be SpamAssassin plugins or built-in classes,
               there's no difference in this respect.  Internally this invokes UNIVERSAL::can.

           can(Name::Of::Package::function_name)
               This is a function call that returns 1 if the perl package named
               "Name::Of::Package" includes a function called "function_name" and that function
               returns a true value when called with no arguments, otherwise "undef" is returned.

               Is similar to "has", except that it also calls the named function, testing its
               return value (unlike the perl function UNIVERSAL::can).  This makes it possible
               for a 'feature' function to determine its result value at run time.

           If the end of a configuration file is reached while still inside a "if" scope, a
           warning will be issued, but parsing will restart on the next file.

           For example:

                   if (version > 3.000000)
                     header MY_FOO ...
                   endif

                   loadplugin MyPlugin plugintest.pm

                   if plugin (MyPlugin)
                     header MY_PLUGIN_FOO  eval:check_for_foo()
                     score  MY_PLUGIN_FOO  0.1
                   endif

       ifplugin PluginModuleName
           An alias for "if plugin(PluginModuleName)".

       else
           Used to support conditional interpretation of the configuration file. Lines between
           this and a corresponding "endif" line, will be ignored unless the conditional
           expression evaluates as false (in the perl sense; that is, not defined and not 0 and
           non-empty string).

       require_version n.nnnnnn
           Indicates that the entire file, from this line on, requires a certain version of
           SpamAssassin to run.  If a different (older or newer) version of SpamAssassin tries to
           read the configuration from this file, it will output a warning instead, and ignore
           it.

           Note: The version used is in the internal SpamAssassin version format which is
           "x.yyyzzz", where x is major version, y is minor version, and z is maintenance
           version.  So 3.0.0 is 3.000000, and 3.4.80 is 3.004080.

TEMPLATE TAGS

       The following "tags" can be used as placeholders in certain options.  They will be
       replaced by the corresponding value when they are used.

       Some tags can take an argument (in parentheses). The argument is optional, and the default
       is shown below.

        _YESNO_           "Yes" for spam, "No" for nonspam (=ham)
        _YESNO(spam_str,ham_str)_  returns the first argument ("Yes" if missing)
                          for spam, and the second argument ("No" if missing) for ham
        _YESNOCAPS_       "YES" for spam, "NO" for nonspam (=ham)
        _YESNOCAPS(spam_str,ham_str)_  same as _YESNO(...)_, but uppercased
        _SCORE(PAD)_      message score, if PAD is included and is either spaces or
                          zeroes, then pad scores with that many spaces or zeroes
                          (default, none)  ie: _SCORE(0)_ makes 2.4 become 02.4,
                          _SCORE(00)_ is 002.4.  12.3 would be 12.3 and 012.3
                          respectively.
        _REQD_            message threshold
        _VERSION_         version (eg. 3.0.0 or 3.1.0-r26142-foo1)
        _SUBVERSION_      sub-version/code revision date (eg. 2004-01-10)
        _RULESVERSION_    comma-separated list of rules versions, retrieved from
                          an '# UPDATE version' comment in rules files; if there is
                          more than one set of rules (update channels) the order
                          is unspecified (currently sorted by names of files);
        _HOSTNAME_        hostname of the machine the mail was processed on
        _REMOTEHOSTNAME_  hostname of the machine the mail was sent from, only
                          available with spamd
        _REMOTEHOSTADDR_  ip address of the machine the mail was sent from, only
                          available with spamd
        _BAYES_           bayes score
        _TOKENSUMMARY_    number of new, neutral, spammy, and hammy tokens found
        _BAYESTC_         number of new tokens found
        _BAYESTCLEARNED_  number of seen tokens found
        _BAYESTCSPAMMY_   number of spammy tokens found
        _BAYESTCHAMMY_    number of hammy tokens found
        _HAMMYTOKENS(N)_  the N most significant hammy tokens (default, 5)
        _SPAMMYTOKENS(N)_ the N most significant spammy tokens (default, 5)
        _DATE_            rfc-2822 date of scan
        _STARS(*)_        one "*" (use any character) for each full score point
                          (note: limited to 50 'stars')
        _SENDERDOMAIN_    a domain name of the envelope sender address, lowercased
        _AUTHORDOMAIN_    a domain name of the author address (the From header
                          field), lowercased;  note that RFC 5322 allows a mail
                          message to have multiple authors - currently only the
                          domain name of the first email address is returned
        _RELAYSTRUSTED_   relays used and deemed to be trusted (see the
                          'X-Spam-Relays-Trusted' pseudo-header)
        _RELAYSUNTRUSTED_ relays used that can not be trusted (see the
                          'X-Spam-Relays-Untrusted' pseudo-header)
        _RELAYSINTERNAL_  relays used and deemed to be internal (see the
                          'X-Spam-Relays-Internal' pseudo-header)
        _RELAYSEXTERNAL_  relays used and deemed to be external (see the
                          'X-Spam-Relays-External' pseudo-header)
        _LASTEXTERNALIP_  IP address of client in the external-to-internal
                          SMTP handover
        _LASTEXTERNALRDNS_ reverse-DNS of client in the external-to-internal
                          SMTP handover
        _LASTEXTERNALHELO_ HELO string used by client in the external-to-internal
                          SMTP handover
        _AUTOLEARN_       autolearn status ("ham", "no", "spam", "disabled",
                          "failed", "unavailable")
        _AUTOLEARNSCORE_  portion of message score used by autolearn
        _TESTS(,)_        tests hit separated by "," (or other separator)
        _TESTSSCORES(,)_  as above, except with scores appended (eg. AWL=-3.0,...)
        _SUBTESTS(,)_     subtests (start with "__") hit separated by ","
                          (or other separator)
        _SUBTESTSCOLLAPSED(,)_ subtests (start with "__") hit separated by ","
                          (or other separator) with duplicated rules collapsed
        _DCCB_            DCC's "Brand"
        _DCCR_            DCC's results
        _PYZOR_           Pyzor results
        _RBL_             full results for positive RBL queries in DNS URI format
        _LANGUAGES_       possible languages of mail
        _PREVIEW_         content preview
        _REPORT_          terse report of tests hit (for header reports)
        _SUBJPREFIX_      subject prefix based on rules, to be prepended to Subject
                          header by SpamAssassin caller
        _SUMMARY_         summary of tests hit for standard report (for body reports)
        _CONTACTADDRESS_  contents of the 'report_contact' setting
        _HEADER(NAME)_    includes the value of a message header.  value is the same
                          as is found for header rules (see elsewhere in this doc)
        _TIMING_          timing breakdown report
        _ADDEDHEADERHAM_  resulting header fields as requested by add_header for spam
        _ADDEDHEADERSPAM_ resulting header fields as requested by add_header for ham
        _ADDEDHEADER_     same as ADDEDHEADERHAM for ham or ADDEDHEADERSPAM for spam

       If a tag reference uses the name of a tag which is not in this list or defined by a loaded
       plugin, the reference will be left intact and not replaced by any value.

       Additional, plugin specific, template tags can be found in the documentation for the
       following plugins:

        L<Mail::SpamAssassin::Plugin::ASN>
        L<Mail::SpamAssassin::Plugin::AWL>
        L<Mail::SpamAssassin::Plugin::TxRep>

       The "HAMMYTOKENS" and "SPAMMYTOKENS" tags have an optional second argument which specifies
       a format.  See the HAMMYTOKENS/SPAMMYTOKENS TAG FORMAT section, below, for details.

   HAMMYTOKENS/SPAMMYTOKENS TAG FORMAT
       The "HAMMYTOKENS" and "SPAMMYTOKENS" tags have an optional second argument which specifies
       a format: "_SPAMMYTOKENS(N,FMT)_", "_HAMMYTOKENS(N,FMT)_" The following formats are
       available:

       short
           Only the tokens themselves are listed.  For example, preference file entry:

           "add_header all Spammy _SPAMMYTOKENS(2,short)_"

           Results in message header:

           "X-Spam-Spammy: remove.php, UD:jpg"

           Indicating that the top two spammy tokens found are "remove.php" and "UD:jpg".  (The
           token itself follows the last colon, the text before the colon indicates something
           about the token.  "UD" means the token looks like it might be part of a domain name.)

       compact
           The token probability, an abbreviated declassification distance (see example), and the
           token are listed.  For example, preference file entry:

           "add_header all Spammy _SPAMMYTOKENS(2,compact)_"

           Results in message header:

           "0.989-6--remove.php, 0.988-+--UD:jpg"

           Indicating that the probabilities of the top two tokens are 0.989 and 0.988,
           respectively.  The first token has a declassification distance of 6, meaning that if
           the token had appeared in at least 6 more ham messages it would not be considered
           spammy.  The "+" for the second token indicates a declassification distance greater
           than 9.

       long
           Probability, declassification distance, number of times seen in a ham message, number
           of times seen in a spam message, age and the token are listed.

           For example, preference file entry:

           "add_header all Spammy _SPAMMYTOKENS(2,long)_"

           Results in message header:

           "X-Spam-Spammy: 0.989-6--0h-4s--4d--remove.php, 0.988-33--2h-25s--1d--UD:jpg"

           In addition to the information provided by the compact option, the long option shows
           that the first token appeared in zero ham messages and four spam messages, and that it
           was last seen four days ago.  The second token appeared in two ham messages, 25 spam
           messages and was last seen one day ago.  (Unlike the "compact" option, the long option
           shows declassification distances that are greater than 9.)

LOCALI[SZ]ATION

       A line starting with the text "lang xx" will only be interpreted if the user is in that
       locale, allowing test descriptions and templates to be set for that language.

       The locales string should specify either both the language and country, e.g.  "lang
       pt_BR", or just the language, e.g. "lang de".

SEE ALSO

       Mail::SpamAssassin(3) spamassassin(1) spamd(1)