My mail server worked perfectly well until I upgraded my domains to SSL using the LetsEncrypt option in Virtualmin. Now I get this bounce message trying to send mail outside the domains hosted on my VPS. Sending between email addresses hosted locally works 100% - just cannot send mail outside my VPS.
I did try all the suggested fixes found all over the internet, but none could solve the problem.
I suspect it has something to do with SSL but I cannot finds any help on that searching.
Message from the mail log: dsn=5.4.6, status=bounced (mail for gmail.com loops back to myself)
I also get a message from the mail log: warning: do not list domain example.com in BOTH mydestination and virtual_alias_domains
Postfix configuration files are basic default.
The latter error means the hostname and domain hosted are identical. While this is just a warning and does not stop things from working it is bad practice to for instance have a server hostname of: