Provided by: postfix-policyd-spf-python_1.0-1_all bug

NAME

       python-policyd-spf - pure-Python Postfix policy daemon for SPF checking

VERSION

       1.0

USAGE

       Usage:
         policyd-spf [/etc/postfix-policyd-spf-python/policyd-spf.conf]

OTHER DOCUMENTATION

       This documentation assumes you have read Postfix's README_FILES/
       SMTPD_POLICY_README and are generally familiar with Sender Policy
       Framework (SPF).  See RFC 4408 for details.

       man 1 policyd-spf provides general operation documentation for this
       package.

       man 5 policyd-spf.peruser provides documentation on setting up and
       using different configuration options on a per user (mail reciepient)
       basis.

SYNOPSIS

       python-policyd-spf operates with a default installed configuration file
       and set of default configuration options that are used if the
       configuration file cannot be found.  These options can be changed by
       changing the installed configuration files or through giving a path to
       an alternate configuration file.

DESCRIPTION

       Configuration options are described here and in the configuration file
       provided with the package.  The provided setup.py installs this
       configuration file in /etc/postfix-policyd-spf-python/.

       Additionally, whitelisting certain IP addresses from SPF checks is
       supported.  This man page and the sample configuration file show the
       format to use.  These options can be adjusted on a per user (mail
       recipient) basis.  Details on per user settings can be found in
       policyd-spf.peruser(5).

OPTIONS

LOGGING

       "debugLevel" controls the amount of information logged by the policy
       server.

       The default, 1, logs no debugging messages, just basic SPF results and
       errors generated through the policy server.  This value can be
       increased up to 5 (values higher than 5 will not cause an error, but
       will not log any additional information).

       debug level 2 adds a log message if no client address (IP address from
       which the connection was made), Mail From addresss, or HELO/EHLO name
       is received by the policy server, and logs SPF results for each Mail
       From and HELO check.

       debug level 3 generates a log message each time the policy server
       starts and each time it exits, as well as logging a copy of the exact
       header returned to Postfix to be prepended into the message.  Each time
       the policy server starts, debug level 3 also logs the configuration
       information used by the policy server.

       debug level 4 logs the complete data set received by Postfix via the
       policy interface and when the end of the entry is read.

       debug level 5 is used to debug config file processing and can only be
       set in code and not via the config file.

       If debug level is 0, then the policy server logs errors only.

       Default:

       debugLevel = 1

TEST OPERATION

       The policy server can operate in a test only mode. This allows you to
       see the potential impact of SPF checking in your mail logs without
       rejecting mail.  Headers are prepended in messages, but message
       delivery is not affected. This mode is not enabled by default.  To
       enable it, set defaultSeedOnly = 0.

       Default:

       defaultSeedOnly = 1

HELO/EHLO CHECKING

       HELO check rejection policy options are:

       SPF_Not_Pass (default) - Reject if result not Pass, None, or Temperror
       (alternatively put, reject if the SPF result is Fail, Softfail,
       Neutral, PermError). Unlike Mail From checking, there are no standard
       e-mail use cases where a HELO check should not Pass if there is an SPF
       record for the HELO name (transparent forwarding, for example, is not
       an issue). Technically this option is not fully RFC 4408 compliant
       since the SPF check for the Mail From identity is mandatory and Neutral
       and None results must be treated the same.  HELO/EHLO is known first in
       the SMTP dialogue and there is no practical reason to waste resources
       on Mail From checks if the HELO check will already cause the message to
       be rejected. These deviations should not cause interoperability
       problems when used for HELO.

       Softfail - Reject on HELO Softfail or Fail.  Technically this option is
       not fully RFC 4408 compliant since the Mail From identity is mandatory,
       but HELO/ EHLO is known first in the SMTP dialogue and there is no
       practical reason to waste resources on Mail From checks if the HELO
       check will already cause the message to be rejected.

       Fail - Reject only on HELO Fail.  Technically this option is not fully
       RFC 4408 compliant since the Mail From identity is mandatory, but
       HELO/EHLO is known first in the SMTP dialogue and there is no practical
       reason to waste resources on Mail From checks if the HELO check will
       already cause the message to be rejected.

       Null - Only reject HELO Fail for Null sender (SPF Classic).  This is
       the approach used by the pre-RFC 4408 reference implementation and many
       of the pre- RFC specifications.  Use of at least this option
       (SPF_Not_Pass or Fail) are preferred) is highly recommended.

       False - Never reject on HELO, append header only. This is useful for
       post-SMTP spam filters such as SpamAssassin.

       No_Check - Never check HELO.  This is only recommended if you are
       calling the policy server twice (once for HELO checks and once for Mail
       From) with two different configuration files.  This approach is useful
       to get both the HELO and Mail From headers prepended to a message.

       Default:

       HELO_reject = SPF_Not_Pass

HELO/EHLO PASS RESTRICTION

       HELO Pass Restriction allows integration with other Postfix access
       controls by provding a user supplied name of a postfix access
       restriction to be applied to a message when the HELO checking result is
       Pass.  The indicated restriction must be an action as defined for a
       Postfix SMTP server access table access(5) and explained in the Postfix
       RESTRICTION CLASS README. The README.per_user_whitelisting file
       provided with this distribution provides examples. Note: A helo pass
       restriction will be the returned result even if the mail from result
       would cause the message to be rejected.

       Example:

       HELO_pass_restriction = helo_passed_spf

       Default:

       None

Mail From CHECKING

       Mail From rejection policy options are:

       SPF_Not_Pass - Reject if result not Pass/None/Tempfail. This option is
       not RFC 4408 compliant since the mail with an SPF Neutral result is
       treated differently than mail with no SPF record and Softfail results
       are not supposed to cause mail rejection.  Global use of this option is
       not recommended. Use per-domain if needed (per-domain usage described
       below).

       Softfail - Reject on HELO Softfail or Fail.  Technically this option is
       not fully RFC 4408 compliant since Softfail results are not supposed to
       cause mail rejection.  Global use of this option is not recommended.
       Use per-domain if needed (per-domain usage described below).

       Fail (default) - Reject on Mail From Fail.

       False - Never reject on Mail From, append header only.  This is useful
       for post-SMTP spam filters such as SpamAssassin.

       No_Check - Never check Mail From/Return Path.  This is only recommended
       if you are calling the policy server twice (once for HELO checks and
       once for Mail From) with two different configuration files.  This
       approach is useful to get both the HELO and Mail From headers prepended
       to a message.  It could also be used to do HELO checking only (because
       HELO checking has a lower false positive risk than Mail From checking),
       but this approach would not be fully RFC 4408 compliant since the Mail
       From identity is mandatory.

       Default:

       Mail_From_reject = Fail

Mail From PASS RESTRICTION

       Mail From Pass Restriction allows integration with other Postfix access
       contlols by provding a user supplied name of a postfix access
       restriction to be applied to a message when the HELO checking result is
       Pass.  The indicated restriction must be an action as defined for a
       Postfix SMTP server access table access(5) and explained in the Postfix
       RESTRICTION CLASS README. Note: A mail from pass restriction will be
       the returned result even if the helo result would cause the message to
       be rejected.

       Example:

       mail_from_pass_restriction = mfrom_passed_spf

       Default:

       None

Limit Rejections To Domains That Send No Mail

       No_Mail - Only reject when SPF indicates the host/domain sends no mail.
       This option will only cause mail to be rejected if the HELO/Mail From
       record is "v=spf1 -all".  This option is useful for rejecting mail in
       situations where the tolerance for rejecting wanted mail is very low.
       It operates on both HELO and Mail From identities if set.

       Default:

       No_Mail = False

Domain Specific Receiver Policy

       Using this option, a list of domains can be defined for special
       processing when messages do not Pass SPF.  This can be useful for
       commonly spoofed domains that are not yet publishing SPF records with
       -all.  Specifically, if mail from a domain in this list has a
       Neutral/Softfail result, it will be rejected (as if it had a Fail
       result).  This option is not supported by RFC 4408, but if needed, it
       is better to do it on a per-domain basis rather than globally.

       Example:

       Reject_Not_Pass_Domains = aol.com,hotmail.com

       Default:

       None

Permanent Error Processing

       Policy for rejecting due to SPF PermError options are:

       True - Reject the message if the SPF result (for HELO or Mail From) is
       PermError.  This has a higher short-term false positive risk, but does
       result in senders getting feedback that they have a problem with their
       SPF record.

       False - Treat PermError the same as no SPF record at all.  This is
       consistet with the pre-RFC usage (the pre-RFC name for this error was
       "Unknown").

       This is a global option that affects both HELO and Mail From scopes
       when checks for that scope are enabled. The only per scope setting that
       can over-ride this is Mail_From/HELO_reject = False/

       Default:

       PermError_reject = False

Temporary Error Processing

       Policy for deferring messages due to SPF TempError options are:

       True - Defer the message if the SPF result (for HELO or Mail From) is
       TempError.  This is the traditional usage and has proven useful in
       reducing acceptance of unwanted messages.  Sometimes spam senders do
       not retry.  Sometimes by the time a message is retried the sending IP
       has made it onto a DNS RBL and can then be rejected.  This is not the
       default because it is possible for some DNS errors that are classified
       as "Temporary" per RFC 4408 to be permanent in the sense that they
       require operator intervention to correct.

       This is a global option that affects both HELO and Mail From scopes
       when checks for that scope are enabled. The only per scope setting that
       can over-ride this is Mail_From/HELO_reject = False/

       False - Treat TempError the same as no SPF record at all.  This is the
       default to minimize false positive risk.

       Default:

       TempError_Defer = False

Prospective SPF Check

       Prospective SPF checking - Check to see if mail sent from the defined
       IP address would pass.  This is useful for outbound MTAs to avoid
       sending mail that would Fail SPF checks when received.  Disable HELO
       checking when using this option.  It's only potentially useful for Mail
       From checking. SPF Received headers are not added when this option is
       used.

       Prospective = 192.168.0.4

       Default:

       None

LOCAL SPF BYPASS LIST

       Do not check SPF for localhost addresses - add to skip addresses to
       skip SPF for internal networks if desired. Defaults are standard IPv4
       and IPv6 localhost addresses. This can also be used, to allow mail from
       local clients submitting mail to an MTA also acting as a Mail
       Submission Agent (MSA) to be skipped.  An x-header is prepended
       indicating SPF checks were skipped due to a local address.  This is a
       trace header only.  Note the lack of spaces in the list.

       Default:

       skip_addresses = 127.0.0.0/8,::ffff:127.0.0.0//104,::1//128

SPF IP WHITELIST

       A comma separated CIDR Notation list of IP addresses to skip SPF checks
       for.  Use this list to whitelist trusted relays (such as a secondary MX
       and trusted forwarders).  An x-header is prepended indicating the IP
       was whitelisted against SPF checks.  This is a trace header only.  Note
       the lack of spaces in the list.

       Example:

       Whitelist = 192.168.0.0/31,192.168.1.0/30

       Default:

       None

SPF DOMAIN WHITELIST

       Domain_Whitelist: List of domains whose sending IPs should be
       whitelisted from SPF checks.  Use this to list trusted forwarders by
       domain name.  Client IP addresses are tested against SPF records
       published by the listed domains.  This is useful for large forwarders
       with complex outbound infrastructures and SPF records.  This option is
       less scalable than the SPF IP Whitelist.  An x-header is prepended
       indicating the IP was whitelisted against SPF checks.  This is a trace
       header only.  This option does nothing if the domain does not have an
       SPF record.  In this case use the SPF IP Whitelist described above or
       Domain_Whitelist_PTR (below). Note the lack of spaces in the list.

       Example:

       Domain_Whitelist = pobox.com,trustedforwarder.org

       Default:

       None

PTR DOMAIN WHITELIST

       Domain_Whitelist_PTR: List of domains (and subdomains)  whose sending
       IPs should be whitelisted from SPF checks based on PTR match of the
       domain. Use this to list trusted forwarders by domain name if they do
       not publish SPF records.  Client IP addresses PTR names are tested to
       see if they match the listed domains.  This is useful for large
       forwarders with complex outbound infrastructures, but no SPF records
       and predictable host naming. Matching is done using the same rules as
       the SPF PTR mechanism as described in RFC 4408.  List the parent domain
       and all subdomains will match. This option is less scalable than the
       SPF IP Whitelist.  An x-header is prepended indicating the IP was
       whitelisted against SPF checks.  This is a trace header only.  This
       option does nothing if the host does not have a PTR record record.  In
       this case use the SPF IP Whitelist described above. Note the lack of
       spaces in the list.

       Example:

       Domain_Whitelist_PTR = yahoo.com,yahoogroups.com

       Default:

       None

RESULTS HEADER

       The standard method for documenting SPF results in a message (for
       consumption by downstream processes) is the Received-SPF header defined
       in RFC 4408. This is the default header to use. Results can also be
       documented in the Authentication-Results header defined by RFC 5451.
       The default is Received-SPF (SPF), but inclusion of Authentication-
       Results (AR) headers as an alternative to Received-SPF can be
       specified.

       If there is a requirement to prepend both Received-SPF and
       Authentication- Results headers, then it must be done by processing the
       message with more than one instance of the policy server using
       different configuration files with different Header_Type settings.

       Examples:

       Header_Type = SPF or Header_Type = AR

       Default:

       SPF

Authentications Results Authentication Identifier

       Every Authentication-Results header field has an authentication
       identifier field ('Authserv_Id'). This is similar in syntax to a fully-
       qualified domain name. See policyd-spf.conf.5 and RFC 5451 paragraph
       2.3 for details.  Default is None.  Authserv-Id must be provided if
       Header_Type 'AR' is used.

       The authentication identifier field provides a unique identifier that
       refers to the authenticating service within a given administrative
       domain. The identifier MUST be unique to that domain.  This identifier
       is intended to be machine-readable and not necessarily meaningful to
       users.

       Example:

       Authserv_Id = mx.example.com

SEE ALSO

       man 1 policyd-spf, man 5 policyd-spf.peruser, python-spf,
       <http://www.openspf.net>, RFC 4408, RFC 5451

AUTHORS

       This version of pypolicyd-spf was written by Copyright (C) 2007-2012,
       Scott Kitterman <scott@kitterman.com>.  It is derived from Tumgreyspf,
       written by Sean Reifschneider, tummy.com, ltd <jafo@tummy.com>.
       Portions of the documentation were written by Meng Weng Wong
       <mengwong@pobox.com>.

       This man-page was created by Scott Kitterman <scott@kitterman.com>.

                                  2012-03-17                policy-spf.conf(5)