Continue to experience problems with this user whos been migrated from 2007 to 2013.
User A logs in as user A but uses a shared mailbox (Called it PA-B) and also has access to mailbox B. They also have access to another user C mailbox.
User A would like be able to send mail as both PA-B and B (so its transparent). Also calendar items.
Initially, all 4 mailboxes were setup in outlook as separate email accounts with PA-B as the default. What we found though was that, somehow, at different times starting outlook, sometimes SEND AS PA-B worked fine, but sometimes, for some reason, it did strange things like send as email as send on behalf user C! It was as if outlook was swapping which user it though it was ! Also, we were getting email stuck in the outbox.... Sent items in random locations.
So now I've created a new profile. Also Ive converted PA-B to be a shared mailbox not a user mailbox. User A and PA-B as mailboxes with user B and C set up as additional mailboxes under these. So far works ok I think.
For this sort of scenario, what would be the recommended setup?