If there are messages stored in the queue there will always be a (temporary) error when delivering to the destination server.
To investigate the issue:
- verify you have set a correct destination route (also ensure there are not multiple destination routes specified, normally there should just be 1 route).
- check the logs on your destination server to investigate why it's not accepting the delivery attempts.
- run a test to check the response of your destination mail server.
- if after following these steps you still have an issue, please contact SpamExperts support providing a sample sender/recipient/date to investigate.
