https://www.pistack.xyz/tags/milter/ Recent content in Milter on Pi Stack Hugo en-us Sun, 10 May 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-05-10-self-hosted-smtp-milter-management-milter-manager-rspamd-opendkim-guide/ Sun, 10 May 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-05-10-self-hosted-smtp-milter-management-milter-manager-rspamd-opendkim-guide/ <p>The Milter (Mail Filter) API is Sendmail and Postfix protocol that allows external programs to inspect and modify email messages during the SMTP transaction. Milters are the backbone of server-side email security — handling spam detection, DKIM signing, virus scanning, content filtering, and policy enforcement. This guide compares three open-source milter implementations: <strong>milter-manager</strong> (unified milter framework), <strong>rspamd</strong> (high-performance spam filter with milter interface), and <strong>OpenDKIM</strong> (DKIM signing and verification via milter).</p>