fe222425_lla_X_Mozilla_Status_explained_X_Mozilla_Status_Description
[Name] MSG_FLAG_EXPUNGED [Value] 0x0008 [Description] 
Already gone (when folder not compacted). Since actually removing a message from a folder is a semi-expensive operation, we tend to delay it; messages with this bit set will be removed the next time folder compaction is done. Once this bit is set, it never gets un-set.
Christian Eyrich - Mozilla X-Mozilla-Status explained
Description