I’ve fixed all the issues I’ve had with Mailcow, but one has stuck. I can’t email one specific domain. Every other email sends just fine.
I ALWAYS get the following in Postfix’s log:
to=<firstname.lastname@example.org>, relay=none, delay=15450, delays=15450/0.02/0/0, dsn=4.4.3, status=deferred (Host or domain name not found. Name service error for name=address.co.za type=MX: Host not found, try again)
and an email that bounces back.
But if I look up using MxToolbox, the address has a valid MX record.
What can I do? I’ve heard of setting postfixes DNS, and tried using
docker exec -ti mailcowdockerized-postfix-mailcow-1 and entering
nameserver 188.8.131.52 into
/var/spool/postfix/etc/resolv.conf, but this hasn’t done anything.
I’ve deleted the file in the meanwhile just incase it does something unexpected.
dig address.co.za MX returns the correct question, answer and additional sections as expected…
Running the above inside the container just hangs there forever… Then times out.