Delivery Temporarily Suspended Unknown Mail Transport Error Postfix Upd |top|

Look 10 lines above the "unknown mail transport error." The true error (e.g., “Name service error,” “Connection timed out,” or “TLS read error”) lives there.

The "temporarily suspended" message is a summary. To find the root cause, search further back in your mail logs (usually /var/log/mail.log /var/log/maillog ) for the initial failure that led to the suspension. /var/log/mail.log | tail -n Use code with caution. Copied to clipboard Verify Configuration Syntax Look 10 lines above the "unknown mail transport error

Or a recursive lookup (domain points to a transport that points back to the same domain). /var/log/mail

proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks If the chroot environment is incomplete, change this

If you are running on a system like CentOS or in a Docker container, check if the smtp service is chrooted in master.cf (look for a y in the 5th column). If the chroot environment is incomplete, change this to n and restart Postfix. Also, ensure /etc/services is readable by the postfix user.