Apache SpamAssassin is free, open-source software that classifies email and helps administrators block unsolicited bulk messages. It runs on a server to filter spam before it reaches a mailbox. Detection combines header and text analysis, Bayesian filtering, DNS blocklists, collaborative filtering databases, and local and network tests. A scoring framework and plugins add heuristic and statistical checks. Tests and configuration are stored in plain text, allowing administrators to change settings and add rules. The Mail::SpamAssassin API can be integrated into email systems including procmail, sendmail, Postfix, and qmail. Its core distribution provides command-line filtering tools and Perl modules for use in other products. The downloads page lists version 4.0.2 as the released version. Official releases are signed with a GPG key, and downloads include links to signatures and SHA-256 and SHA-512 checksums. Users can ask questions on the mailing list, where developers and PMC members respond as time permits. The project advises administrators to replace the default report-template contact details with their own support desk information. SpamAssassin is licensed as open-source software.
Who it is for
SpamAssassin suits system administrators who manage email servers and can configure filtering rules or integrate Perl modules. It is intended for server-side spam filtering before messages reach users' mailboxes.
What is good
- Combines Bayesian, DNS, collaborative, and content analysis.
- Plain-text rules and configuration can be customized.
- API supports procmail, sendmail, Postfix, and qmail.
- Official downloads include signature and checksum links.
What to know first
- Runs on a server rather than as a listed end-user app.
- Mailing-list responses are provided as time permits.
- Administrators should replace default report-template contact details.
Verdict
SpamAssassin gives administrators several filtering methods and configurable rules, with an API for integration into supported mail systems. It requires server-side setup and ongoing administrative attention, including updating the report-template contact details.
Apache SpamAssassin plans and pricing
All plansCompared on email anti-spam software
- Phishing detection
- Yes
- Malware scanning
- Yes
- Attachment scanning
- Yes
- Supported mail platforms
- procmail, sendmail, Postfix, qmail
- Deployment type
- self_hosted
