NAME
    spamassassin - extensible email filter used to identify spam

DESCRIPTION
    SpamAssassin is an intelligent email filter which uses a diverse range
    of tests to identify unsolicited bulk email, more commonly known as
    "spam". These tests are applied to email headers and content to classify
    email using advanced statistical methods. In addition, SpamAssassin has
    a modular architecture that allows other technologies to be quickly
    wielded against spam and is designed for easy integration into virtually
    any email system.

SYNOPSIS
    For ease of access, the SpamAssassin manual has been split up into
    several sections. If you're intending to read these straight through for
    the first time, the suggested order will tend to reduce the number of
    forward references.

    Extensive additional documentation for SpamAssassin is 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)

  CONFIGURATION
        Mail::SpamAssassin::Conf  SpamAssassin configuration files

  USAGE
        spamassassin-run          "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

WEB SITES
        SpamAssassin web site:     https://spamassassin.apache.org/
        Wiki-based documentation:  https://wiki.apache.org/spamassassin/

USER MAILING LIST
    A users mailing list exists where other experienced users are often able
    to help and provide tips and advice. Subscription instructions are
    located on the SpamAssassin web site.

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

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

    /var/lib/spamassassin/4.000001
    /usr/local/share/spamassassin
    /usr/local/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/local/etc/mail/spamassassin
    /usr/local/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, 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.

    Individual user preferences are loaded from the location specified on
    the "spamassassin", "sa-learn", or "spamd" command line (see respective
    manual page for details). If the location is not 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/local/etc/mail/spamassassin
    /usr/local/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: 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.

  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).

    The new report message inherits the following headers (if they are
    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).

    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.

    Note that 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.

    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://issues.apache.org/SpamAssassin/>

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

COPYRIGHT AND LICENSE
    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