How to determine the last time a mailbox sent/received email. I have a list of mailboxes. I need to determine if they are still in use. No one seems to know the answer. I'm thinking that the modified date tells me the last time that mailbox has sent or received email. Correct? If I"m correct, how do I get that info, Modified Date? I don't know my way around Exchange 2010 to view individual mailboxes and see their properties.