I need to run my own email server for some of my domains, because the providers that I usually use don’t support them (they use Unicode characters, and not everyone supports that yet). I have a small VPS that I run a few Docker containers on, and I’m wanting to try and run an email server on it as well. What containers are good for a low-hassle email setup? I don’t need a mailbox webui (ex: roundcube), but it would be nice to have a UI for management. I do need multi-domain support, however.
EDIT: For anyone wondering, I decided to go with Mailu. Stalwart didn’t play will with internationalized domains (although it was the only server to support EAI/SMTPUTF8), and Mailcow would have been a bit more difficult for me to change to bind mounts and reconfigure Docker networking with.
All MTAs have retries baked in, so running a self-hosted email server that receives mail is actually one of the most forgiving services in this respect. If your server is offline, the sending server will retry several times over 24-48 hours before it gives up. Even the big cloud email providers will do this.
That said, there are other aspects of running an email server that require some extra rigour, but they’re more on the sending side (making sure emails you send to other people actually land in their inbox). Doable, but one of the more challenging things to self-host.