We recently did an Office 365 Migration from in-house Exchange. All the mailboxes converted perfectly except for one. The bad mailbox has lots of white space and missing entries. We created a new mailbox in office 365 and imported a pst file from the original Exchange Server That mailbox now contains all the information we need for that user. We called the new mailbox usertest, as opposed to user. Is there a way for us to assign the actual user to the new mailbox with his original email address? I know I can delete the bad account, recreate it and then import a pst file into it, but was wondering if there was a quick way within Exchange.