How does the Exchange 2000 Server Mailbox Manager decide which messages to remove?
The Microsoft article "XADM: Exchange 2000 Server SP1 Mailbox Manager" (http://support.microsoft .com/support/kb/articles/q278/0/24 .asp) details how the Exchange 2000 Mailbox Manager works, including how you configure it and what it can do. In brief, the manager examines the timestamp on each message to decide whether the message is old enough to meet the removal policy requirements. For ordinary mail messages (i.e., IPM.Note-type messages), the system checks three separate Messaging API (MAPI) properties: the time the message was delivered (PR_MESSAGE_ DELIVERY_TIME), the time the client submitted the message (PR_CLIENT_ SUBMIT_TIME), and the time of its last modification (PR_LAST_MODIFI CATION _TIME). If any of these three times isn't older than the recipient policy, Mailbox Manager won't delete the message. For tasks, journal entries, and appointments, Mailbox Manager checks additional fields: recurring appointments and uncompleted tasks will never be deleted, nor will items whose start or end dates are in the future.