Hi every body 🙂 I’m trying to set up a discourse forum, and I already have a working mailcow setup for my domain. Discourse requires an SMTP relay to send out transactional emails, and want to use my mailcow server for this.
What I tried:
The discourse config looks like this
where email@example.com is a working account on my mailcow setup with the password “password”, and I’ve successfully sent mail from it before in a client like thunderbird with these credentials.
When discourse tries to send a mail, I get the error
Reason: 533 5.7.1 <firstname.lastname@example.org>: Sender address rejected: not owned by user email@example.com
I’ve also tried sending mail directly with telnet and didn’t succeed, but probably because I’m not familiar with it. Trying to authenticate over starttls like in this thread https://stackoverflow.com/questions/27030605/smtp-starttls-certificate-negotitiation-via-telnet I get a kind of weird reply
openssl s_client -debug -starttls smtp -crlf -connect mail.example.tld:587
firstname.lastname@example.org (encoded in base64)
password (encoded in base 64)
>132463048316736:error:1420410A:SSL routines:SSL_renegotiate:wrong ssl version:ssl/ssl_lib.c:2140:
I’m not sure how to tell what the right version of ssl is, nor why it only failed after sending credentials, when earlier it negotiated the certificates just fine.
And if I try without TLS I get what I would have expected
telnet mail.example.tld 25
503 5.5.1 Error: authentication not enabled
I guess I can connect to the smtp relay (and email clients can send mail no problem!), but there’s something I need to configure differently, and I don’t really understand what the right question to ask is. Can any body help?