Question

As a site admin, it'd be useful to be able to set up a regular expression to be run against all incoming email and process common fields (From, To, CC, Subject, Body) prior to any other processing by the FogBugz server. On a successful match, further processing of the email would be abandoned.

Two main reasons:

1. New cases being created, e.g., when an Escalation Report bounces off someone who has an automated out-of-office reply turned on.
2. Cases being reactivated by the mail server's undeliverable mail response when they're resolved or closed when, e.g., a contractor is no longer in the system. This one results in a potentially endless resolve-reactivate cycle that can frustrate users who don't understand what's happening.

Answer 1

I have posted a feature request for a more general ability to filter messages. You can vote for it here. For your specific needs, I would try:

1. Create an area in your Inbox for bounces and/or out of office replies. When one creates a new case, move it there and auto-sort will eventually pick up. We use that here at Fog Creek and it works well.
2. This sounds like a bigger problem: a mail loop. If you have users in FogBugz who no longer have valid email addresses, the best thing to do is edit them to turn off their email notifications.