Is something like this going to go?Simply block port 25/tcp for all customers, only whitelist it for specific customers upon request. Nobody needs it nowadays, except a few people still running mail servers on premises.
How to autodetect infected or spammer users and temporary block the SMTP output...Can you be more specific on what type of spam you are concerned about??
Try upgrading them from 6.44.6 to 6.46.4 and they will not be able to communicate normallyI have Dude 6.46.4 and many RBs 6.44.6, and they all are talking with Dude.