Ubuntu Manpage: Mail::SpamAssassin - Spam detector and markup engine

Provided by: spamassassin_3.4.2-0ubuntu0.18.04.5_all

NAME

       Mail::SpamAssassin - Spam detector and markup engine

SYNOPSIS

         my $spamtest = Mail::SpamAssassin->new();
         my $mail = $spamtest->parse($message);
         my $status = $spamtest->check($mail);

         if ($status->is_spam()) {
           $message = $status->rewrite_mail();
         }
         else {
           ...
         }
         ...

         $status->finish();
         $mail->finish();
         $spamtest->finish();

DESCRIPTION

       Mail::SpamAssassin is a module to identify spam using several methods including text analysis, internet-
       based realtime blacklists, statistical analysis, and internet-based hashing algorithms.

       Using its rule base, it uses a wide range of heuristic tests on mail headers and body text to identify
       "spam", also known as unsolicited bulk email.  Once identified as spam, the mail can then be tagged as
       spam for later filtering using the user's own mail user agent application or at the mail transfer agent.

       If you wish to use a command-line filter tool, try the "spamassassin" or the "spamd"/"spamc" tools
       provided.

METHODS

$t = Mail::SpamAssassin->new( { opt => val, ... } )
Constructs a new "Mail::SpamAssassin" object. You may pass a hash reference to the constructor which
may contain the following attribute- value pairs.

debug
This is the debug options used to determine logging level. It exists to allow sections of debug
messages (called "facilities") to be enabled or disabled. If this is a string, it is treated as
a comma-delimited list of the debug facilities. If it's a hash reference, then the keys are
treated as the list of debug facilities and if it's a array reference, then the elements are
treated as the list of debug facilities.

There are also two special cases: (1) if the special case of "info" is passed as a debug
facility, then all informational messages are enabled; (2) if the special case of "all" is passed
as a debug facility, then all debugging facilities are enabled.

rules_filename
The filename/directory to load spam-identifying rules from. (optional)

site_rules_filename
The filename/directory to load site-specific spam-identifying rules from. (optional)

userprefs_filename
The filename to load preferences from. (optional)

userstate_dir
The directory user state is stored in. (optional)

config_tree_recurse
Set to 1 to recurse through directories when reading configuration files, instead of just reading
a single level. (optional, default 0)

config_text
The text of all rules and preferences. If you prefer not to load the rules from files, read them
in yourself and set this instead. As a result, this will override the settings for
"rules_filename", "site_rules_filename", and "userprefs_filename".

pre_config_text
Similar to "config_text", this text is placed before config_text to allow an override of config
files.

post_config_text
Similar to "config_text", this text is placed after config_text to allow an override of config
files.

force_ipv4
If set to 1, DNS or other network tests will prefer IPv4 and not attempt to use IPv6. Use if the
existing tests for IPv6 availability produce incorrect results or crashes.

force_ipv6
For symmetry with force_ipv4: if set to 1, DNS or other network tests will prefer IPv6 and not
attempt to use IPv4. Some plugins may disregard this setting and use whatever protocol family
they are comfortable with.

require_rules
If set to 1, init() will die if no valid rules could be loaded. This is the default behaviour
when called by "spamassassin" or "spamd".

languages_filename
If you want to be able to use the language-guessing rule "UNWANTED_LANGUAGE_BODY", and are using
"config_text" instead of "rules_filename", "site_rules_filename", and "userprefs_filename", you
will need to set this. It should be the path to the languages file normally found in the
SpamAssassin rules directory.

local_tests_only
If set to 1, no tests that require internet access will be performed. (default: 0)

need_tags
The option provides a way to avoid more expensive processing when it is known in advance that
some information will not be needed by a caller.

A value of the option can either be a string (a comma-delimited list of tag names), or a
reference to a list of individual tag names. A caller may provide the list in advance, specifying
his intention to later collect the information through $pms->get_tag() calls. If a name of a tag
starts with a 'NO' (case insensitive), it shows that a caller will not be interested in such tag,
although there is no guarantee it would save any resources, nor that a tag value will be empty.
Currently no built-in tags start with 'NO'. A later entry overrides previous one, e.g.
ASN,NOASN,ASN,TIMING,NOASN is equivalent to TIMING,NOASN.

For backward compatibility, all tags available as of version 3.2.4 will be available by default
(unless disabled by NOtag), even if not requested through need_tags option. Future versions may
provide new tags conditionally available.

Currently the only tag that needs to be explicitly requested is 'TIMING'. Not requesting it can
save a millisecond or two - it mostly serves to illustrate the usage of need_tags.

Example:
need_tags => 'TIMING,noLANGUAGES,RELAYCOUNTRY,ASN,noASNCIDR', or:
need_tags => [qw(TIMING noLANGUAGES RELAYCOUNTRY ASN noASNCIDR)],

ignore_site_cf_files
If set to 1, any rule files found in the "site_rules_filename" directory will be ignored. *.pre
files (used for loading plugins) found in the "site_rules_filename" directory will still be used.
(default: 0)

dont_copy_prefs
If set to 1, the user preferences file will not be created if it doesn't already exist. (default:
0)

save_pattern_hits
If set to 1, the patterns hit can be retrieved from the "Mail::SpamAssassin::PerMsgStatus"
object. Used for debugging.

home_dir_for_helpers
If set, the HOME environment variable will be set to this value when using test applications that
require their configuration data, such as Razor, Pyzor and DCC.

username
If set, the "username" attribute will use this as the current user's name. Otherwise, the
default is taken from the runtime environment (ie. this process' effective UID under UNIX).

skip_prng_reseeding
If skip_prng_reseeding is set to true, the SpamAssassin library will not call srand() to reseed a
pseudo-random number generator (PRNG). The srand() Perl function should be called during
initialization of each child process, soon after forking.

Prior to version 3.4.0, calling srand() was handled by the SpamAssassin library.

This setting requires the caller to decide when to call srand(). This choice may be desired to
preserve the entropy of a PRNG. The default value of skip_prng_reseeding is false to maintain
backward compatibility.

This option should only be set by a caller if it calls srand() upon spawning child processes.
Unless you are certain you need it, leave this setting as false.

NOTE: The skip_prng_reseeding feature is implemented in spamd as of 3.4.0 which allows spamd to
call srand() right after forking a child process.

If none of "rules_filename", "site_rules_filename", "userprefs_filename", or "config_text" is set,
the "Mail::SpamAssassin" module will search for the configuration files in the usual installed
locations using the below variable definitions which can be passed in.

PREFIX
Used as the root for certain directory paths such as:

'__prefix__/etc/mail/spamassassin'
'__prefix__/etc/spamassassin'

Defaults to "@@PREFIX@@".

DEF_RULES_DIR
Location where the default rules are installed. Defaults to "@@DEF_RULES_DIR@@".

LOCAL_RULES_DIR
Location where the local site rules are installed. Defaults to "@@LOCAL_RULES_DIR@@".

LOCAL_STATE_DIR
Location of the local state directory, mainly used for installing updates via "sa-update" and
compiling rulesets to native code. Defaults to "@@LOCAL_STATE_DIR@@".

parse($message, $parse_now [, $suppl_attrib])
Parse will return a Mail::SpamAssassin::Message object with just the headers parsed. When calling
this function, there are two optional parameters that can be passed in: $message is either undef
(which will use STDIN), a scalar - a string containing an entire message, a reference to such string,
an array reference of the message with one line per array element, or either a file glob or an
IO::File object which holds the entire contents of the message; and $parse_now, which specifies
whether or not to create a MIME tree at parse time or later as necessary.

The $parse_now option, by default, is set to false (0). This allows SpamAssassin to not have to
generate the tree of internal data nodes if the information is not going to be used. This is handy,
for instance, when running "spamassassin -d", which only needs the pristine header and body which is
always parsed and stored by this function.

The optional last argument $suppl_attrib provides a way for a caller to pass additional information
about a message to SpamAssassin. It is either undef, or a ref to a hash where each key/value pair
provides some supplementary attribute of the message, typically information that cannot be deduced
from the message itself, or is hard to do so reliably, or would represent unnecessary work for
SpamAssassin to obtain it. The argument will be stored to a Mail::SpamAssassin::Message object as
'suppl_attrib', thus made available to the rest of the code as well as to plugins. The exact list of
attributes will evolve through time, any unknown attribute should be ignored. Possible examples are:
SMTP envelope information, a flag indicating that a message as supplied by a caller was truncated due
to size limit, an already verified list of DKIM signature objects, or perhaps a list of rule hits
predetermined by a caller, which makes another possible way for a caller to provide meta information
(instead of having to insert made-up header fields in order to pass information), or maybe just plain
rule hits.

For more information, please see the "Mail::SpamAssassin::Message" and
"Mail::SpamAssassin::Message::Node" POD.

$status = $f->check ($mail)
Check a mail, encapsulated in a "Mail::SpamAssassin::Message" object, to determine if it is spam or
not.

Returns a "Mail::SpamAssassin::PerMsgStatus" object which can be used to test or manipulate the mail
message.

Note that the "Mail::SpamAssassin" object can be re-used for further messages without affecting this
check; in OO terminology, the "Mail::SpamAssassin" object is a "factory". However, if you do this,
be sure to call the "finish()" method on the status objects when you're done with them.

$status = $f->check_message_text ($mailtext)
Check a mail, encapsulated in a plain string $mailtext, to determine if it is spam or not.

Otherwise identical to "check()" above.

$status = $f->learn ($mail, $id, $isspam, $forget)
Learn from a mail, encapsulated in a "Mail::SpamAssassin::Message" object.

If $isspam is set, the mail is assumed to be spam, otherwise it will be learnt as non-spam.

If $forget is set, the attributes of the mail will be removed from both the non-spam and spam
learning databases.

$id is an optional message-identification string, used internally to tag the message. If it is
"undef", the Message-Id of the message will be used. It should be unique to that message.

Returns a "Mail::SpamAssassin::PerMsgLearner" object which can be used to manipulate the learning
process for each mail.

"learn()" and "check()" can be run using the same factory. "init_learner()" must be called before
using this method.

$f->init_learner ( [ { opt => val, ... } ] )
Initialise learning. You may pass the following attribute-value pairs to this method.

caller_will_untie
Whether or not the code calling this method will take care of untie'ing from the Bayes databases
(by calling "finish_learner()") (optional, default 0).

force_expire
Should an expiration run be forced to occur immediately? (optional, default 0).

learn_to_journal
Should learning data be written to the journal, instead of directly to the databases? (optional,
default 0).

wait_for_lock
Whether or not to wait a long time for locks to complete (optional, default 0).

opportunistic_expire_check_only
During the opportunistic journal sync and expire check, don't actually do the expire but report
back whether or not it should occur (optional, default 0).

no_relearn
If doing a learn operation, and the message has already been learned as the opposite type, don't
re-learn the message.

$f->rebuild_learner_caches ({ opt => val })
Rebuild any cache databases; should be called after the learning process. Options include:
"verbose", which will output diagnostics to "stdout" if set to 1.

$f->finish_learner ()
Finish learning.

$f->dump_bayes_db()
Dump the contents of the Bayes DB

$f->signal_user_changed ( [ { opt => val, ... } ] )
Signals that the current user has changed (possibly using "setuid"), meaning that SpamAssassin should
close any per-user databases it has open, and re-open using ones appropriate for the new user.

Note that this should be called after reading any per-user configuration, as that data may override
some paths opened in this method. You may pass the following attribute-value pairs:

username
The username of the user. This will be used for the "username" attribute.

user_dir
A directory to use as a 'home directory' for the current user's data, overriding the system
default. This directory must be readable and writable by the process. Note that the resulting
"userstate_dir" will be the ".spamassassin" subdirectory of this dir.

userstate_dir
A directory to use as a directory for the current user's data, overriding the system default.
This directory must be readable and writable by the process. The default is
"user_dir/.spamassassin".

$f->report_as_spam ($mail, $options)
Report a mail, encapsulated in a "Mail::SpamAssassin::Message" object, as human-verified spam. This
will submit the mail message to live, collaborative, spam-blocker databases, allowing other users to
block this message.

It will also submit the mail to SpamAssassin's Bayesian learner.

Options is an optional reference to a hash of options. Currently these can be:

dont_report_to_dcc
Inhibits reporting of the spam to DCC.

dont_report_to_pyzor
Inhibits reporting of the spam to Pyzor.

dont_report_to_razor
Inhibits reporting of the spam to Razor.

dont_report_to_spamcop
Inhibits reporting of the spam to SpamCop.

$f->revoke_as_spam ($mail, $options)
Revoke a mail, encapsulated in a "Mail::SpamAssassin::Message" object, as human-verified ham (non-
spam). This will revoke the mail message from live, collaborative, spam-blocker databases, allowing
other users to block this message.

It will also submit the mail to SpamAssassin's Bayesian learner as nonspam.

Options is an optional reference to a hash of options. Currently these can be:

dont_report_to_razor
Inhibits revoking of the spam to Razor.

$f->add_address_to_whitelist ($addr, $cli_p)
Given a string containing an email address, add it to the automatic whitelist database.