Exchange to IMAP Gateway

I am one of this users that is still using client mail like Thunderbird. Do not get me wrong, I use and like Gmail, but I still need more control over my mail in few cases. Anyway, from time to time the University Exchange server is updated/reconfigured and I loose access to the provided IMAP access. Since this became recurrent event and the suggested solutions from the support team were somewhat random guesses I looked for alternative solution.

Here is what I am using right now, while I can not access my mail box after the last upgrade.