Recently I've had problems connected to an Exchange server configured with IMAP. The configuration used to work until the system updated to 16.0.1. - now I get: "Connection to Server XXX timed out error" each time I connect.
Although I sit behind a proxy, Thunderbird has no problems finding extensions or add-ons (which suggests that the internet works) and I have tested the IMAP server with an earlier version of Thunderbird (3.x) on Windows and got lots of e-mail which suggest the server works.
Is anyone else having this problem or if not are there any tips for generating more information on the situation?