Email on Cumps · Geek.

SPF, DKIM, DMARC: Getting Mail Delivered

Tue, 08 Sep 2026 10:00:00 +0200

Last week ended with Stalwart running on two nodes. At that point I had a mail server in the same sense that a teenager with a learner’s permit has a car: technically true, not yet trusted by anyone. The big providers treat unknown mail servers as guilty until proven innocent, and the proof is a stack of DNS records and protocols that grew up as patches on a protocol from 1982.

One Binary for All of Email

Tue, 01 Sep 2026 10:00:00 +0200

Email is the service this whole project exists for, and the one my family will not forgive me for breaking. It’s also the service with the scariest reputation in self-hosting. Part of that reputation comes from the traditional stack: Postfix for SMTP, Dovecot for IMAP, rspamd for spam, something else for CalDAV, each with its own config language, its own failure modes, and its own opinions about the others.