Rspamd vs Sublime Security

Rspamd is an email security engine for filtering phishing, business email compromise, malicious attachments, and spam. It scores messages using reputation, sender authentication, content analysis, and machine learning. Authentication checks cover SPF, DKIM, DMARC, and ARC; malware scanning can use ClamAV or commercial antivirus engines. Administrators can define custom rules through the Lua API and configurable maps and selectors. Rspamd works with mail transfer agents including Postfix, Exim, and Sendmail, and its ClickHouse and Elasticsearch integrations provide visibility into attack patterns and detection rates. It is designed for gateway deployment and can run on-premises, keeping message data in the operator's environment without a mandatory vendor cloud. The detection engine is open source under Apache 2.0 and is available for Linux, macOS, and self-hosted use. Rspamd says its event-driven C core scans hundreds of messages per second per core and can scale from a single server to billions of messages a day. The open-source engine is listed at free. Scale costs £100 a month, with 5K mailboxes; hosted and enterprise plans have custom pricing. Premium plans offer support from core engineers, with enterprise SLA options.

Sublime Security has no write-up on Specifiction yet; its figures are above.