Understanding SpamAssassin¶

SpamAssassin is a mail filtering system that evaluates messages using a collection of rules. Rules can identify patterns associated with junk mail, suspicious links, forged sender information, and authentication failures.

How scoring works¶

Each matching rule contributes a score. A higher total generally means the message looks more like spam to the filter. The configured threshold determines whether the message is tagged, moved, or otherwise handled. Thresholds and available actions depend on your mail configuration.

The score is a signal, not proof. A legitimate message can match several rules, and a harmful message can score below the configured threshold.

Review a message¶

1. Open the message’s full headers or source in your email app.
2. Look for SpamAssassin fields such as X-Spam-Status, X-Spam-Score, and X-Spam-Report when present.
3. Review the listed rule names to see what contributed to the score.
4. Check authentication results such as SPF, DKIM, and DMARC separately. A spam score alone does not confirm who sent a message.
5. If a legitimate message is consistently misclassified, ask your mail administrator to review the matched rules and threshold before adding an allowlist entry.

Header fields vary by server and may be removed or rewritten by forwarding services. See Spam Score and Header Analysis for more details.