Problem: I'm seeing the below message:
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
retry time not reached for any host after a long failure period
The Exchange server at that IP had been down for some time (Issues on their end) and the time exceeded the max time. Once the server came back up, mail was still bouncing with the above message.
Because this was a static route I had setup in /etc/staticroutes, the system was bouncing mail instead of sending it on. I tried everything listed in the forum, but couldn't bypass the issue. Finally in desperation, I touched the /etc/staticroutes file and that allowed mail to flow again.
So if mail on a static route is not going to a remote server, try touching the routes file....