Weird issue with Office 365.
We setup a new user who is using the same account name as an old user. The old user was deleted a long time ago. When the new user setup their mailbox on a totally different computer the mail from the old user was loaded into the mailbox.
Old user: Bob Smith
Old user account name: BSmith@domain.com
New user: Brian Smith
New user account name: BSmith@domain.com
Bob smith's old mailbox loads into Brian Smiths new mailbox.
This is all on Office 365 with dirsync. The old exchange server has all mailboxes deleted and is currently off.
The old user was deleted a long time ago.