Testing further, I see that with TB 1.5.0.9, using a filter on a custom header for an IMAP account works correctly, both for arriving mail and running the filters on the Inbox.
With 2b2, the filters run as expected on arriving mail, but not after-the-fact.
Magnus, is that what you see (per comment 20) or are you seeing a problem with arriving mail?
Testing further, I see that with TB 1.5.0.9, using a filter on a custom header for an IMAP account works correctly, both for arriving mail and running the filters on the Inbox.
With 2b2, the filters run as expected on arriving mail, but not after-the-fact.
Magnus, is that what you see (per comment 20) or are you seeing a problem with arriving mail?