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.
Common problems and solutions
ClamAV fails to scan for viruses
May 7 12:42:28 debian amavis: (01834-01) (!)run_av (ClamAV-clamd) FAILED - unexpected , output="/var/lib/amavis/tmp/amavis-20110507T124228-01834/parts: lstat() failed: Permission denied. ERROR\n"
You forgot to run
adduser clamav amavis
Missing indentation in the master.cf
The /etc/postfix/master.cf file needs proper indentation. The first line of each service starts in the first column. Additional lines of the same service need to be indented by spaces.
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".
I get "Permission denied" from Dovecot in the mail.log file
You have the permissions wrong. Run:
chmod -R vmail:vmail /var/vmail
Why is the database not normalized (email addresses with domain in virtual_users table)?
It's possible to normalize the database and use the JOIN syntax to get the domain name from the virtual_domains table. But that would lead to string operations when Postfix and Dovecot look up a certain email address. This quickly becomes a performance penalty when you have many users. So in this case performance wsas rated higher than strict normalisation.