InTrust Plug-in for Exchange tracks mailbox access made using Microsoft Outlook and Outlook Web Access email clients. If an access is made, the InTrust Plug-in for Exchange Service generates a separate event for each kind of activity for every mailbox object. It is not quite clear, though, if non-MAPI access events are tracked.
Tracking access through IMAP and POP3 is limited and not officialy supported.
1. Only owner access events can be tracked for POP3 and IMAP4, non-owner access events are not captured.
2. For owner-access events, only Receive and Delete events are tracked; Read-events are not.