I installed Unity, and integrated with Active directory and exchange 2003. When a user send a text messages from the outlook to another user, he ckecks the option Request a read receipt, when the other user read the message, the MWI puts ON of the phone from the first user that send the message when receive the confirmation. then this cause that the mailbox be full for that user.
Sorry for my english
Jose Luis Arango Carvajal