just realized that for a few hours my mailcow server became an open relay and was happily sending spam. Given various community posts this seems to be a quite common beginner issue :/
I am certain that I ran a relay check a few weeks ago. So any idea what can turn MC into open relay?
Now I just want to make sure that I’ve not been compromised and of course that this will not happen ever again … Any steps I should follow? From what I saw in abuse reports I’d tend to say that the sender was not auth’ed.
Actually I did not disable IPv6 on the system itself but was blocking IPv6 traffic on host level plus had configured disable_ipv6 true according to docs. The only thing I missed was the override for ipv6nat-mailcow.
Could that have caused my issue?
Sorry for the newbie’ish question but while I’m quite into linux I just got a basic understanding of docker and mailcow.