General troubleshooting tips
- Run “postfix check” to make Postfix look for obvious configuration errors. If it returns no output then no problem was found.
- Read your /var/log/mail.log and look for warnings and errors.
Postfix keeps unwanted emails in the queue
Check that you do not keep soft_bounce enabled. If “postconf soft_bounce” shows “yes” then run “postconf soft_bounce=no”. To remove all emails from your queue (dangerous!) run “postsuper -d ALL”.
I get “Permission denied” from Dovecot in the mail.log file
You have the permissions wrong. Run:
chown -R vmail:vmail /var/vmail
Postfix says: “Mail loops back to myself”
Postfix tried to send an email to the internet because it did not feel responsible for the recipient’s domain. However DNS records pointed it back to itself. So either your DNS record for a certain domain is wrong (unlikely) or your Postfix refuses to receive email for the given domain (very likely). Check that the recipient’s domain is listed in the “virtual_domains” table in the MySQL database. And verify that your CF files are working correctly