I'm getting this message for one of the mail accounts on my system:
Diagnostic-Code: X-Postfix; cannot append message to file /username: cannot
create file exclusively: Permission denied
I earlier deleted /var/spool/mail/username.lock for this user and may also have temporarily moved /var/spool/mail/username. The permissions for /var/spool/mail/username are:
-rw-r--r-- 1 username mail 0 May 6 00:08 /var/spool/mail/username
I don't know why this mail account is getting messages returned. What could be causing this error message?