>>>I'm going to upgrade to office 2016 on Monday, hopefully it will end my misery.
>>
>>By "losing connection", do you mean that you are asked for username and password?
>
>No, the status is displayed as disconnected and it's not connecting again until I re-start.

Sorry, then I can't help. I have had cases where I have been asked to enter username and password after Outlook has been running for a very long time. I found at that this happened because someone, probably some hackers, tried to access my account. When they try too many times with the wrong password, other users to the same account is thrown out and must log in again.