Delivery Temporarily Suspended Unknown Mail Transport Error Postfix Upd — Complete & Trusted

setenforce 0 (temporarily). If the error stops, SELinux is blocking the transport.

Postfix expects a service named dovecot to be explicitly defined in your master.cf file. If it is missing or misspelled, the unknown transport error occurs. Verify master.cf Service Definitions setenforce 0 (temporarily)

This usually means Postfix attempted handoff to a transport (local delivery agent, external SMTP, or a pipeline like fetchmail/procmail/virtual) and that transport returned a non-specific/unknown error. Steps to find and fix it: setenforce 0 (temporarily)