Rspamd vs Xeams

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.

Xeams is an email server and spam firewall that can run standalone, sit in front of another mail server, or operate in hybrid mode. It supports SMTP, POP3, and IMAP, alongside email technologies including DKIM, SPF, DMARC, and MTA-STS. Filtering uses sender reputation, authentication checks, attachment and content rules, Bayesian analysis, and virus checks. Administrators use a web interface for live monitoring, logs, reports, retention settings, and tiered administration. Quarantined messages are kept on the server for 15 days by default and can be reached through the web interface or an IMAP client. Integrations include Active Directory and OAuth 2.0 outbound relaying for services such as Microsoft Exchange Online or Google Workspace. Outbound tools include DKIM signing, REST APIs, webhooks, campaigns, read receipts, and header sanitization. A new installation has Enterprise features for 30 days before converting to Community Edition unless licensed. Community Edition is free for up to 5 personal hobby users when spam filtering is used; its spam filtering is otherwise limited to 5 users. Enterprise Edition with Support is $300 a year per deployed instance; Enterprise per-user prices vary by tier.