I'am as a web developer, often use Virtualmin as Control Panel, but sometimes when configuring i got stuck with the following error. After some research i got the solution to fix the error. I wrote here as reminder for future and also for you if stuck with the same error.
"Your Postfix configuration is missing the system's mail hostname UNKNOWN from the mydestination line, which will cause mail to bounce."
Solution:
Put "UNKNOWN" string inside "/etc/postfix/main.cf" file and in line "mydestination ="
Hope this writing can help you out there.
"Your Postfix configuration is missing the system's mail hostname UNKNOWN from the mydestination line, which will cause mail to bounce."
Put "UNKNOWN" string inside "/etc/postfix/main.cf" file and in line "mydestination ="
Hope this writing can help you out there.