Today's email processing delay has been corrected.
We're in the process of rebuilding the server farm that runs asynchronous maintenance tasks like search indexing and email processing for FogBugz On Demand. It turns out that the email processing task for cases@youraccount.fogbugz.com addresses silently failed with our new configuration, but we didn't notice until we brought down the last of the old servers today.
We implemented a quick-fix about half an hour ago and most delayed emails should have been processed by now. A permanent fix that includes noisy failure will go out with our next FogBugz On Demand deployment.