I have an exchange 2010 server that I have moved all my mailboxes to from a 2003 server. I have 4 mailboxes that are shared mailboxes. Groups of users attach them as secondary mailboxes to the primary outlook profile. The permissions appear to be setup the same on all of these mailboxes. 3 of the mailboxes work as expected 1 of them does not. When these users send an e-mail from these maiboxes they allways change the From: field to be that mailbox so the receipient does not see an indiviuals name or e-mail address. They also always copy that mailbox on the message. (I have no idea why but that is their process) 3 of these shared mailboxes work perfectly. The one mailbox sends the e-mail out as expected but the message that goes out is put in the sent items of that mailbox and marked as an unread message. No message ever appears in the inbox as it does with the other shared mailboxes. if the from field is not populated it works fine but then the message is sent from the end user not the shared mailbox.