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/mail/spamassassin directories.

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

https://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.

WELCOMELIST AND BLOCKLIST OPTIONS

welcomelist_from user@example.com

Previously whitelist_from which will work interchangeably until 4.1.

Used to welcomelist 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 welcomelist_auth or other authenticated welcomelisting methods, or welcomelist_from_rcvd.

Welcomelist and blocklist 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 welcomelist_from lines are also OK.

The headers checked for welcomelist 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.

welcomelist_from joe@example.com fred@example.com
welcomelist_from *@example.com

unwelcomelist_from user@example.com

Previously unwelcomelist_from which will work interchangeably until 4.1.

Used to remove a default welcomelist_from entry, so for example a distribution welcomelist_from can be overridden in a local.cf file, or an individual user can override a welcomelist_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 welcomelist_from line, which implies that a wildcard only matches literally the same wildcard (not 'any' address).

e.g.

unwelcomelist_from joe@example.com fred@example.com
unwelcomelist_from *@example.com

welcomelist_from_rcvd addr@lists.sourceforge.net sourceforge.net

Previously whitelist_from_rcvd which will work interchangeably until 4.1.

Works similarly to welcomelist_from, except that in addition to matching a sender address, a relay's rDNS name or its IP address must match too for the welcomelisting rule to fire. The first parameter is a sender's e-mail address to welcomelist, 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.

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

def_welcomelist_from_rcvd addr@lists.sourceforge.net sourceforge.net

Previously def_whitelist_from_rcvd which will work interchangeably until 4.1.

Same as welcomelist_from_rcvd, but used for the default welcomelist entries in the SpamAssassin distribution. The welcomelist score is lower, because these are often targets for spammer spoofing.

welcomelist_allows_relays user@example.com

Previously whitelist_allows_relays which will work interchangeably until 4.1.

Specify addresses which are in welcomelist_from_rcvd that sometimes send through a mail relay other than the listed ones. By default mail with a From address that is in welcomelist_from_rcvd that does not match the relay will trigger a forgery rule. Including the address in welcomelist_allows_relay prevents that.

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

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

e.g.

welcomelist_allows_relays joe@example.com fred@example.com
welcomelist_allows_relays *@example.com

unwelcomelist_from_rcvd user@example.com

Previously unwhitelist_from_rcvd which will work interchangeably until 4.1.

Used to remove a default welcomelist_from_rcvd or def_welcomelist_from_rcvd entry, so for example a distribution welcomelist_from_rcvd can be overridden in a local.cf file, or an individual user can override a welcomelist_from_rcvd entry in their own user_prefs file.

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

e.g.

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

blocklist_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 welcomelist_from.

unblocklist_from user@example.com

Previously unblacklist_from which will work interchangeably until 4.1.

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

e.g.

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

welcomelist_to user@example.com

Previously whitelist_to which will work interchangeably until 4.1.

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

There are three levels of To-welcomelisting, welcomelist_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 welcomelist 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.

blocklist_to user@example.com

Previously blacklist_auth which will work interchangeably until 4.1.

If the given address appears as a recipient in the message headers (Resent-To, To, Cc, obvious envelope recipient, etc.) the mail will be blocklisted. Same format as blocklist_from.

welcomelist_auth user@example.com

Previously whitelist_auth which will work interchangeably until 4.1.

Used to specify addresses which send mail that is often tagged (incorrectly) as spam. This is different from welcomelist_from and welcomelist_from_rcvd in that it first verifies that the message was sent by an authorized sender for the address, before welcomelisting.

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 welcomelist_auth is roughly equivalent to specifying duplicate welcomelist_from_spf, welcomelist_from_dk, and welcomelist_from_dkim lines for each of the addresses specified.

e.g.

welcomelist_auth joe@example.com fred@example.com
welcomelist_auth *@example.com

def_welcomelist_auth user@example.com

Previously def_whitelist_auth which will work interchangeably until 4.1.

Same as welcomelist_auth, but used for the default welcomelist entries in the SpamAssassin distribution. The welcomelist score is lower, because these are often targets for spammer spoofing.

unwelcomelist_auth user@example.com

Previously unwhitelist_auth which will work interchangeably until 4.1.

Used to remove a welcomelist_auth or def_welcomelist_auth entry. The specified email address has to match exactly the address previously used.

e.g.

unwelcomelist_auth joe@example.com fred@example.com
unwelcomelist_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 'BLOCK' and 'WELCOME' have their shorthand directives blocklist_uri_host and welcomelist_uri_host and corresponding default rules, but the names 'BLOCK' and 'WELCOME' 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 blocklist_to is synonymous to using the directive blocklist_to.

Enlisting an address to the list named blocklist_from is synonymous to using the directive blocklist_from.

Enlisting an address to the list named welcomelist_to is synonymous to using the directive welcomelist_to.

Enlisting an address to the list named welcomelist_from is synonymous to using the directive welcomelist_from.

e.g.

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

blocklist_uri_host host-or-domain ...

Previously blacklist_uri_host which will work interchangeably until 4.1.

Is a shorthand for a directive: enlist_uri_host (BLOCK) host ...

Please see directives enlist_uri_host and delist_uri_host for details.

welcomelist_uri_host host-or-domain ...

Previously whitelist_uri_host which will work interchangeably until 4.1.

Is a shorthand for a directive: enlist_uri_host (WELCOME) 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 when the glue between the MTA and SpamAssassin rewrites the email content.

Here is an example on how to use this feature:

rewrite_header Subject *****SPAM*****
add_header all Subjprefix _SUBJPREFIX_
body     OLEMACRO_MALICE eval:check_olemacro_malice()
describe OLEMACRO_MALICE Dangerous Office Macro
score    OLEMACRO_MALICE 5.0
if can(Mail::SpamAssassin::Conf::feature_subjprefix)
  subjprefix OLEMACRO_MALICE [VIRUS]
endif

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.

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: 75)

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: 1)

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.

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 blocklist checks will never query for hosts on these networks.

See https://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 module Net::CIDR::Lite is installed, it's also possible to use dash separated IP range format (e.g. 192.168.1.1-192.168.255.255).

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: none)

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.

A default list may be supplied via sa-update, use clear_originating_ip_headers to clear and override the settings if needed.

clear_originating_ip_headers

Empty the list of 'originating IP address' header field names. Useful if you want to override the standard list supplied by sa-update.

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: Blockhole 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: v4, v6, norotate, nodns0x20, edns=4096)

Provides a (whitespace or comma -separated) list of options applying to DNS resolving. Available options are: v4, v6, 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 v4 declares resolver capable of returning IPv4 (A) records. Option v6 declares resolver capable of returning IPv6 (AAAA) records. One would set nov6 if the resolver is filtering AAAA responses. NOTE: these options only refer to resolving capabilies, there is no other meaning like whether the IP address of resolver itself is IPv4 or IPv6.

Option edns (or edns0) 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.

Special wildcard "dns_query_restriction deny *" is supported to block all queries except allowed ones.

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).

dns_block_rule RULE domain

If rule named RULE is hit, DNS queries to specified domain are temporarily blocked. Intended to be used with rules that check RBL return codes for specific blocked status. For example:

urirhssub URIBL_BLOCKED multi.uribl.com. A 1
dns_block_rule URIBL_BLOCKED multi.uribl.com

Block status is maintained across all processes by empty statefile named "dnsblock_multi.uribl.com" in global state dir: home_dir_for_helpers/.spamassassin, $HOME/.spamassassin, /var/lib/spamassassin (localstate), depending which is found and writable.

dns_block_time (default: 300)

dns_block_rule query blockage will last this many seconds.

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. Header matching is case-insensitive. 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 welcomelist_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 welcomelisting or blocklisting 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. https://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: UTF-8)

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/mail/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 https://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 blocklist or welcomelist). 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, 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 welcomelist), 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 https://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.

Body is processed as a raw byte string, which means Unicode-specific regex features like \p{} can NOT be used for matching. The normalize_charset setting will also affect how raw bytes are presented. Rules in .cf files should be written portably - to match "a with umlaut" character, look for both LATIN1 and UTF8 raw byte variants: /(?:\xE4|\xC3\xA4)/

All body paragraphs (double-newline-separated blocks text) are turned into a linebreaks-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".

See https://wiki.apache.org/SpamAssassin/WritingRules for more information.

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.

Note that CRLF/LF line endings are matched as the original message has them. For any full rules that match newlines, it's recommended to use \r?$ instead of plain $, so it works on all systems.

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-welcomelist. 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