Apache SpamAssassin vs Sophos Secure Message

Apache SpamAssassin is free, open-source software that classifies email to help system administrators block unsolicited bulk messages. It runs on a server to filter mail before it reaches a mailbox. Detection combines header and text analysis, Bayesian filtering, DNS blocklists, collaborative filtering databases, and local and network tests. Its scoring framework and plugins add heuristic and statistical checks. Tests and configuration are stored as plain text, so administrators can adjust settings and add rules. The Mail::SpamAssassin API can be integrated with systems such as procmail, sendmail, Postfix, and qmail. The core distribution includes 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 GPG signatures and SHA-256 and SHA-512 checksum links for downloads. Users can ask questions on the mailing list; developers and PMC members answer as time permits.

Sophos Secure Message is part of Sophos Email, a cloud service for protecting inboxes from phishing, business email compromise, spam, and email-delivered malware. Sophos Email uses AI and machine-learning models, natural-language processing, sender authentication, URL rewriting, and attachment sandboxing to detect threats. Post-delivery protection can retrieve messages later identified as malicious after they reach inboxes. Organizations can set Secure Message policies for selected users, groups, domains, and external recipients. Outbound policies support TLS, S/MIME, push encryption, and portal encryption. With portal encryption, recipients can read and reply to encrypted messages through a secure web portal without maintaining their own encryption infrastructure. Multi-rule data-protection and content-control policies can detect sensitive email data and encrypt it automatically. Sophos Email integrates with Microsoft 365 and Google Workspace and connects threat telemetry with Sophos MDR and XDR. Secure Message policies cannot be configured in Sophos Email Monitoring System mode. A free trial is available through an active Sophos Fusion account or the trial form. Pricing is on request, and there is no free plan.