[zcdziura]

That's very interesting. I never thought to relay mail internally to dkimproxy. I'll have to give that a shot. I like the idea of hosting the entire solution myself and not relying on any 3rd party solutions, but relaying through SMTP2Go was the only thing that I tried that actually solved the problem. Perhaps this will offer a good solution! Thanks!

[wahern]

I also use the dkimproxy package, but there's now a third-party OpenSMTPd module that can sign messages in-line.[1] I've always found dkimproxy setup a little confusing compared to a built-in/in-line solution. I might try to switch to the module during the OpenBSD 7.1 upgrade process.

[1] I think this is the one I had I mind, though I didn't realize it was already in ports: https://cvsweb.openbsd.org/ports/mail/opensmtpd-filters/dkim...

[throw0101a]

If you run a mailing list you generally have to worry about ARC (re-signing 'chain of custody') in addition to DKIM:

* https://en.wikipedia.org/wiki/Authenticated_Received_Chain

I've found ARC to fiddle some to get going than ARC.