User logs in as user A but default account in outlook is set to user B (for which they have full permissions). They also have a few other additional accounts of type exchange listed (inc their own). (Not as additional mailboxes under the main account but a list of email accounts in account settings.
Problem is that previously they could do send as user B and it'd go in the user B sent items. Now they've been migrated to 2013.
New email items Sent as user B go into the user B sent items - which is what user wants. BUT if you reply to any email even though you set From: to user B it still goes into the sent items folder of the logged in user A.
Is this default behaviour and is there any way to change this?