SPAMASSASSIN(1)

📦
version 4.0.2 · 10 versions
, in alpine 3.23

💌 SPAMASSASSIN 💌 (that's the manual name, bestie — spamassassin(1), User Contributed Perl Documentation)

✨ NAME ✨

spamassassin — the extensible email filter that sniffs out spam, no cap

🦋 DESCRIPTION 🦋

Okay so, SpamAssassin is this intelligent email filter, right? It runs a whole diverse range of tests to figure out what's unsolicited bulk email — aka "spam", the villain of your inbox. Those tests get applied to email headers and content, and then it classifies the email using advanced statistical methods. Fancy. 💅

Plus — and this is the iconic part — SpamAssassin has a modular architecture, so other technologies can be quickly wielded against spam, and the whole thing is designed for easy integration into virtually any email system. Literally any. She's flexible like that. 🧚

🌸 SYNOPSIS 🌸

For ease of access (and honestly, so you don't get overwhelmed, bestie), the SpamAssassin manual has been split up into several sections. If you're planning to read these straight through for the first time, the suggested order will tend to reduce the number of forward references. Trust the order. 🫶

There's also extensive additional documentation for SpamAssassin available — primarily on the SpamAssassin web site and wiki.

You should be able to view SpamAssassin's documentation with your man(1) program or perldoc(1).

👑 OVERVIEW

  • spamassassin — SpamAssassin overview (this section, the one you're in right now, hi 🎀)

🎀 CONFIGURATION

  • Mail::SpamAssassin::Conf — SpamAssassin configuration files

💖 USAGE

  • spamassassin-run — the "spamassassin" front-end filtering script
  • sa-learn — train SpamAssassin's Bayesian classifier
  • spamc — client for spamd (faster than spamassassin)
  • spamd — spamassassin server (needed by spamc)

🌈 DEFAULT PLUGINS

  • Mail::SpamAssassin::Plugin::AskDNS
  • Mail::SpamAssassin::Plugin::AutoLearnThreshold
  • Mail::SpamAssassin::Plugin::Bayes
  • Mail::SpamAssassin::Plugin::BodyEval
  • Mail::SpamAssassin::Plugin::Check
  • Mail::SpamAssassin::Plugin::DKIM
  • Mail::SpamAssassin::Plugin::DMARC
  • Mail::SpamAssassin::Plugin::DNSEval
  • Mail::SpamAssassin::Plugin::FreeMail
  • Mail::SpamAssassin::Plugin::HTMLEval
  • Mail::SpamAssassin::Plugin::HTTPSMismatch
  • Mail::SpamAssassin::Plugin::HashBL
  • Mail::SpamAssassin::Plugin::HeaderEval
  • Mail::SpamAssassin::Plugin::ImageInfo
  • Mail::SpamAssassin::Plugin::MIMEEval
  • Mail::SpamAssassin::Plugin::MIMEHeader
  • Mail::SpamAssassin::Plugin::Pyzor
  • Mail::SpamAssassin::Plugin::Razor2
  • Mail::SpamAssassin::Plugin::RelayEval
  • Mail::SpamAssassin::Plugin::ReplaceTags
  • Mail::SpamAssassin::Plugin::SPF
  • Mail::SpamAssassin::Plugin::SpamCop
  • Mail::SpamAssassin::Plugin::URIDNSBL
  • Mail::SpamAssassin::Plugin::URIDetail
  • Mail::SpamAssassin::Plugin::URIEval
  • Mail::SpamAssassin::Plugin::VBounce
  • Mail::SpamAssassin::Plugin::WLBLEval
  • Mail::SpamAssassin::Plugin::WelcomeListSubject

That's the whole squad, all 28 of them. 💀

🦋 WEB SITES 🦋

💜 USER MAILING LIST 💜

There's a users mailing list where other experienced users are often able to help and provide tips and advice. Subscription instructions are located on the SpamAssassin web site. Go lurk, go learn, iykyk. 🌸

⭐ CONFIGURATION FILES ⭐

The SpamAssassin rule base, text templates, and rule description text are all loaded from configuration files.

Default configuration data is loaded from the first existing directory in:

/var/lib/spamassassin/4.000002
/usr/share/spamassassin
/usr/share/spamassassin
/usr/local/share/spamassassin
/usr/share/spamassassin

Site-specific configuration data is used to override any values which had already been set. This is loaded from the first existing directory in:

/etc/mail/spamassassin
/usr/etc/mail/spamassassin
/usr/etc/spamassassin
/usr/local/etc/spamassassin
/usr/pkg/etc/spamassassin
/usr/etc/spamassassin
/etc/mail/spamassassin
/etc/spamassassin

From those directories, SpamAssassin will first read files ending in ".pre" in lexical order, and then it will read files ending in ".cf" in lexical order (most files begin with two numbers to make the sorting order obvious).

In other words — and yes this is the actual example — it will read init.pre first, then 10_default_prefs.cf before 50_scores.cf, and 20_body_tests.cf before 20_head_tests.cf. Options in later files will override earlier files. Later = boss. 👑

Individual user preferences are loaded from the location specified on the "spamassassin", "sa-learn", or "spamd" command line (see the respective manual page for details). If the location isn't specified, ~/.spamassassin/user_prefs is used if it exists. SpamAssassin will create that file if it does not already exist, using user_prefs.template as a template. That file will be looked for in:

/etc/mail/spamassassin
/usr/etc/mail/spamassassin
/usr/share/spamassassin
/etc/spamassassin
/etc/mail/spamassassin
/usr/local/share/spamassassin
/usr/share/spamassassin

🌈 TAGGING 🌈

The following two sections detail the default tagging and markup that takes place for messages when running "spamassassin" or "spamc" with "spamd" in the default configuration.

Note bestie: before header modification and addition, all headers beginning with X-Spam- are removed — to prevent spammer mischief, and also to avoid potential problems caused by prior invocations of SpamAssassin. Clean slate energy. 🧼

💅 TAGGING FOR SPAM MAILS

By default, all messages with a calculated score of 5.0 or higher are tagged as spam.

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 and easier to recover). Iconic, non-destructive behaviour. 🫶

The new report message inherits the following headers (if they're present) from the original spam message:

  • From: header
  • To: header
  • Cc: header
  • Subject: header
  • Date: header
  • Message-ID: header

The above headers can be modified if the relevant "rewrite_header" option is given (see "Mail::SpamAssassin::Conf" for more information).

By default these message headers are added to spam:

  • X-Spam-Flag: header — set to "YES".

The headers that added are fully configurable via the "add_header" option (see "Mail::SpamAssassin::Conf" for more information).

  • spam mail body text — the SpamAssassin report is added to top of the mail message body, if the message is marked as spam.

🌸 DEFAULT TAGGING FOR ALL MAILS

These headers are added to all messages, both spam and ham (non-spam). Equal opportunity tagging.

  • X-Spam-Checker-Version: header — the version and subversion of SpamAssassin and the host where SpamAssassin was run.
  • X-Spam-Level: header — a series of "*" characters where each one represents a full score point.
  • X-Spam-Status: header — a string, "(Yes|No), score=nn required=nn tests=xxx,xxx autolearn=(ham|spam|no|unavailable|failed)", is set in this header to reflect the filter status. For the first word, "Yes" means spam and "No" means ham (non-spam).

The headers that added are fully configurable via the "add_header" option (see "Mail::SpamAssassin::Conf" for more information).

🎀 INSTALLATION 🎀

The spamassassin command is part of the Mail::SpamAssassin Perl module. Install this as a normal Perl module, using perl -MCPAN -e shell, or by hand. 💅

Heads up: it is not possible to use the "PERL5LIB" environment variable to affect where SpamAssassin finds its perl modules — due to limitations imposed by perl's "taint" security checks. Sorry bestie, security says no. 🙈

For further details on how to install, please read the "INSTALL" file from the SpamAssassin distribution.

🔥 DEVELOPER DOCUMENTATION 🔥

  • Mail::SpamAssassin — Spam detector and markup engine
  • Mail::SpamAssassin::ArchiveIterator — find and process messages one at a time
  • Mail::SpamAssassin::AutoWelcomelist — auto-welcomelist handler for SpamAssassin
  • Mail::SpamAssassin::Bayes — determine spammishness using a Bayesian classifier
  • Mail::SpamAssassin::BayesStore — Bayesian Storage Module
  • Mail::SpamAssassin::BayesStore::SQL — SQL Bayesian Storage Module Implementation
  • Mail::SpamAssassin::Conf::LDAP — load SpamAssassin scores from LDAP database
  • Mail::SpamAssassin::Conf::Parser — parse SpamAssassin configuration
  • Mail::SpamAssassin::Conf::SQL — load SpamAssassin scores from SQL database
  • Mail::SpamAssassin::Message — decode, render, and hold an RFC-2822 message
  • Mail::SpamAssassin::Message::Metadata — extract metadata from a message
  • Mail::SpamAssassin::Message::Node — decode, render, and make available MIME message parts
  • Mail::SpamAssassin::PerMsgLearner — per-message status (spam or not-spam)
  • Mail::SpamAssassin::PerMsgStatus — per-message status (spam or not-spam)
  • Mail::SpamAssassin::PersistentAddrList — persistent address list base class
  • Mail::SpamAssassin::Plugin — SpamAssassin plugin base class
  • Mail::SpamAssassin::Plugin::RelayCountry — add message metadata indicating the country code of each relay
  • Mail::SpamAssassin::Plugin::SPF — perform SPF verification tests
  • Mail::SpamAssassin::Plugin::URIDNSBL — look up URLs against DNS blocklists
  • Mail::SpamAssassin::SQLBasedAddrList — SpamAssassin SQL Based Auto Welcomelist

💀 BUGS 💀

See <https://bz.apache.org/SpamAssassin/> — yes, fr fr, that's the whole section. Go report it. 🐛

👑 AUTHORS 👑

The SpamAssassin(tm) Project <https://spamassassin.apache.org/>

SpamAssassin is distributed under the Apache License, Version 2.0, as described in the file "LICENSE" included with the distribution.

Copyright (C) 2015 The Apache Software Foundation

Okay that's the whole page, bestie — you made it to the end, main character energy fr fr 💖 This was spamassassin(1) served up with perl v5.42.0, dated 2025-08-31. Slay. Now go filter some email. 🌟

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