I have setup a Postfix mail server that use a relay mail server to deliver the emails. The problem I am having is that from time to time the relay server goes crazy and block my relay username/password and the emails on postfix are lost when the emails bounce after the relay server reject the authentication.
Here is an error example:
to=<email@example.com>, relay=mail.relay-server.net[0.0.0.0]:587, delay=0.57, delays=0.01/0/0.57/0, dsn=5.7.8, status=bounced (SASL authentication failed; server mail.relay-server.net[0.0.0.0] said: 535 5.7.8 Bad username or password (Authentication failed).)
So, my question is is there any way I can setup for Postfix to hold the messages in queue if the relay server start issuing those messages?