Environment: Using IMAP over SSL. Running on Linux with PSM installed. Reproduced by: 1) Mark a message for deletion by pressing the "delete" key or using the contextual menu on the message's line in the inbox. The message gets marked and next message is loaded. 2) Select the deleted message and try to undelete it by marking it as deleted (either by pressing "delete" or using the contextual menu). I'm assuming this is the appropriate method for trying to unmark a message for deletion as this is how NS 4.x handled it and there is no "undelete" option available. The message remains marked for deletion and the next message is loaded. There doesn't seem to be a way to remove the delete flag without logging out and using another IMAP client to remove the delete flag.

*** This bug has been marked as a duplicate of 59694 ***

Verified as a duplicate.