---
name: "Mail::SpamAssassin::Plugin::Bayes"
section: "3pm"
platform: "linux"
package: "spamassassin"
version: "4.0.2-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Mail::SpamAssassin::Plugin::Bayes"
---

# Mail::SpamAssassin::Plugin::Bayes(3pm)

determine spammishness using a Bayesian classifier

## NAME

Mail::SpamAssassin::Plugin::Bayes - determine spammishness using a Bayesian classifier

## DESCRIPTION

This is a Bayesian-style probabilistic classifier, using an algorithm based on the one detailed in Paul Graham's *A Plan For Spam* paper at:

```
  http://www.paulgraham.com/spam.html
```

It also incorporates some other aspects taken from Graham Robinson's webpage on the subject at:

```
  http://radio.weblogs.com/0101454/stories/2002/09/16/spamDetection.html
```

And the chi-square probability combiner as described here:

```
  http://www.linuxjournal.com/print.php?sid=6467
```

The results are incorporated into SpamAssassin as the BAYES\_\* rules.

## USER SETTINGS

- 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.

  Custom regular expressions for additional languages can be defined in `"local.cf"`.

  Custom regular expressions can be specified by using the `"bayes_stopword_lang"` keyword like in the following example:

  ```
   bayes_stopword_languages en se
   bayes_stopword_en (?:you|me)
   bayes_stopword_se (?:du|mig)
  ```

  Regexps are case-insensitive will be anchored automatically at beginning and end.

  To disable stopwords usage, specify `"bayes_stopword_languages disable"`.

  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).

- bayes\_max\_token\_length (default: 15)

  Configure the maximum number of character a token could contain