Mail::...::Bayes(3pm)

💖 NAME 💖

Mail::SpamAssassin::Plugin::Bayes — bestie, this is the plugin that figures out how spammish your mail is using a Bayesian classifier 🦋

---

✨ DESCRIPTION ✨

Okay so this is a Bayesian-style probabilistic classifier (yes, probabilistic, we love a little math moment 🔥), and it runs on an algorithm based on the one Paul Graham laid out in his A Plan For Spam paper, which lives right here:

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

It also steals some other bits and pieces from Graham Robinson's webpage about the whole thing, over at:

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

And it's got the chi-square probability combiner too, as described here:

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

Then all of those results get folded into SpamAssassin as the BAYES_* rules. It's giving iconic, honestly 👑

---

🎀 USER SETTINGS 🎀

• bayes_stopword_languages lang — (default: en)

This one decides which languages are switched on for bayes stopwords processing. Every language comes with a default stopwords regexp, and any token that matches that regular expression will not be considered during bayes processing 💅

Wanna add custom regular expressions for extra languages? You can define them in local.cf. No cap. 🙈

You do that by using the bayes_stopword_lang keyword, like so:

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

Heads up: these regexps are case-insensitive and they get anchored automatically at the beginning and at the end 🔒

And if you want stopwords usage gone, just say bayes_stopword_languages disable. Simple as that.

Only one bayes_stopword_languages or bayes_stopword_xx configuration line can be used. A new configuration line will override the old one — for example, the ones from the SpamAssassin default ruleset (60_bayes_stopwords.cf). So don't be shocked when your old line just... vanishes bestie 💀

• bayes_max_token_length — (default: 15)

This sets the maximum number of characters a token is allowed to contain. That's it, that's the whole vibe ✨

---

That's the whole thing, my love — go forth and classify 🌸

perl v5.40.1 · 2026-07-23 · mwah, tiny sign-off, you're welcome 🫶