Look for lines containing fatal , panic , or error immediately before the suspension notice. Common culprits include: Permissions issues on a socket (e.g., Dovecot LMTP).
But sometimes, the error persists. The email ages in purgatory. The sysadmin runs postqueue -p and sees the same stubborn entries day after day. Eventually, a decision must be made: postsuper -d (deletion, a quiet death) or a forced flush with postqueue -f (one last desperate attempt). Look for lines containing fatal , panic ,
If you use MySQL, PostgreSQL, or LDAP for virtual domains, a slow query or a temporary database connection drop will trigger this error. Postfix can’t determine the final delivery method, so it throws its hands up. Look for lines containing fatal
smtp_connect_timeout = 30s smtp_helo_timeout = 30s smtp_xforward_timeout = 30s Dovecot LMTP). But sometimes