[BizTalk] Cleanup MessageBox

To cleanup unprocessed messsages in message box, BizTalk Server provides a SQL stored procedure.

Here're steps to cleanup unprocessed message:

1. Do IISRESET.
2. Stop all BizTalk application and host instances
3. Open SQL server management console, browse to [BizTalkMsgBoxDb].
4. Execute bts_CleanupMsgbox stored procedure on BizTalkMsgBoxDb
5. Execute bts_PurgeSubscriptions stored procedure on BizTalkMsgBoxDb
6. Restart Biztalk server

Now your messages are deleted. And you have a emppy message box now :)