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.IX Title "Mail::SpamAssassin::Plugin::Bayes 3"
.TH Mail::SpamAssassin::Plugin::Bayes 3 2024-09-01 "perl v5.40.0" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
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.SH NAME
Mail::SpamAssassin::Plugin::Bayes \- determine spammishness using a Bayesian classifier
.SH DESCRIPTION
.IX Header "DESCRIPTION"
This is a Bayesian-style probabilistic classifier, using an algorithm based on
the one detailed in Paul Graham's \fIA Plan For Spam\fR paper at:
.PP
.Vb 1
\&  http://www.paulgraham.com/spam.html
.Ve
.PP
It also incorporates some other aspects taken from Graham Robinson's webpage
on the subject at:
.PP
.Vb 1
\&  http://radio.weblogs.com/0101454/stories/2002/09/16/spamDetection.html
.Ve
.PP
And the chi-square probability combiner as described here:
.PP
.Vb 1
\&  http://www.linuxjournal.com/print.php?sid=6467
.Ve
.PP
The results are incorporated into SpamAssassin as the BAYES_* rules.
.SH "USER SETTINGS"
.IX Header "USER SETTINGS"
.IP "bayes_stopword_languages lang             (default: en)" 4
.IX Item "bayes_stopword_languages lang (default: en)"
Languages enabled in bayes stopwords processing, every language have a
default stopwords regexp, tokens matching this regular expression will not
be considered in bayes processing.
.Sp
Custom regular expressions for additional languages can be defined in \f(CW\*(C`local.cf\*(C'\fR.
.Sp
Custom regular expressions can be specified by using the \f(CW\*(C`bayes_stopword_lang\*(C'\fR
keyword like in the following example:
.Sp
.Vb 3
\& bayes_stopword_languages en se
\& bayes_stopword_en (?:you|me)
\& bayes_stopword_se (?:du|mig)
.Ve
.Sp
Regexps are case-insensitive will be anchored automatically at beginning and
end.
.Sp
To disable stopwords usage, specify \f(CW\*(C`bayes_stopword_languages disable\*(C'\fR.
.Sp
Only one bayes_stopword_languages or bayes_stopword_xx configuration line
can be used.  New configuration line will override the old one, for example
the ones from SpamAssassin default ruleset (60_bayes_stopwords.cf).
.IP "bayes_max_token_length (default: 15)" 4
.IX Item "bayes_max_token_length (default: 15)"
Configure the maximum number of character a token could contain