In Outlook 2010 and above Microsoft introduced a new feature of having multiple Exchange accounts in the same Outlook profile. Prior to this version of Outlook, you couldn't do that. Whilst this is a good thing, it does cause some problems for our friendly Enterprise Vault Outlook Add-in.
Because of the way in which the Outlook Add-in works, the primary Exchange account has to be EV enabled. In my situation below my 'rob' account IS archiving enabled, and the other account is not. If the primary / default mailbox isn't enabled, you'll get a pop-up like this:
So if you have:
.. the pop-up is displayed, and you have no EV functionality even though one of the mailboxes does have EV archiving enabled.
If you have:
.. things will work.
Unfortunately there isn't a way around this.