We are aware of an issue affecting mail flow following a recent hotfix that was pushed out. This is due to Amavis not starting back up on a number of SpamTitan instances.  We are currently working on getting this resolved as quickly as possible.

Update:  A hotfix has been deployed to fix the problem.  Systems should automatically pick it up w/in the hour 

--> around Saturday afternoon on 17 Dec  at 2:30 PM ET US / 7:30 PM GMT

You can check the status of the Amavisd in Reporting > System Information > Services