 IMAP, for good or ill
Have the user press the "Purge" (or "Expunge") button on the Outlook Express toolbar. That will permanently get rid of all messages with a line through them.
You're running into one of the, uh, questionable things about the IMAP protocol. Deleting things is a 2-step protocol -- first, you mark things for deletion, and later you "expunge" these marked items. Until you expunge them, they'll stick around... no matter how long you wait. All IMAP servers should work this way, because that's what the RFC demands. |