My spam appliance is passing emails with attachment through. I checked and they are not being blocked. However when the email with attachment reaches the Cas server the email is gone. Checking the log I find the below
A message with the Internal Message ID ### was rejected by the remote server. This message will be deferred and retried because it was marked for retry if rejected. Other messages may also have encountered this error.
It is happening to all emails with attachment (both in internal + external). Everything was fine a couple of days ago so not sure what is happening.
I do have journaling on and I checked the journaling appliance and the email with attachment does not make it there either