Part of twisted.mail.relaymanager View Source View In Hierarchy
|Method||notifySuccess||a relay sent a message successfully|
|Method||notifyFailure||Relaying the message has failed.|
|Method||notifyDone||A relaying SMTP client is disconnected.|
|Method||notifyNoConnection||Relaying SMTP client couldn't connect.|
Mark it as sent in our lists
unmark all pending messages under this relay's responsibility as being relayed, and remove the relay.
Useful because it tells us our upstream server is unavailable.