I have been in the company 10 years... so its changed a few times.

For about 3 years I used a plug in I paid $20 for (after a trial) that was money well spent for me.

Then I think thunderbird and lightening (for calendar) started everything better natively than the plug in sp I went to just native setup.

There is a group of Linux users who kinda support each other also so I wrote up a post on how to get it all working.

Then I'll be honest about 2 or three years ago we moved to office 365, and when I configured it I think everything just magically started working.

And by working I mean getting better at each release.

It now allows native OAuth2 over imap which I think was a huge step in making it play nice.

I use plugins: lookout (not sure what this does), tbsync with provider for Exchange and provider for Google Calendar (this syncs across all my devices).

I just had a look there so I can give people an idea...

Got well over 100k emails in the work account (office365).

Bout 15k In my shammy gmail

Use proton mail bridge also which is another nice program.

I'm on Ubuntu.

I'm trying not to dox myself here lol

Heh thanks for the info. I was just trying the Office 365 IMAP directly, and for my organization Thunderbird is blocked. I looked around to see if I could easily modify it's Application Id (I mean, it's just telling the server what it is...) but could only find instructions for Evolution. Maybe that's something they will add at some point...

I use this one and can definitely recommend it: https://www.beonex.com/owl/

Works very well, calendar too

The plugin worked well for some time for me, but support is really bad. I once had an issue, where the OWA page would require me to log in again, but of course they f'ed up their login to require JS and that JS did not run in Thunderbird (does any?). The plugin then only showed me the login page. When I contacted them, I basically got a shoulder shrugg as an answer, close to "Ah that's bad for you.". Then a while ago my e-mail account in Thunderbird simply disappeared and I still have no idea why and am assuming the plugin had a bug, which deleted the account from my Thunderbird. Haven't put any effort in yet to get it back working and am using IMAP, unable to confirm calendar events and such, because Outlook also wont load in Firefox for me. Good job ...

ActiveSync for contacts and calendar and Cal/Card DAV are now supported for free by the TbSync plugin.

https://addons.thunderbird.net/de/thunderbird/addon/tbsync/?...

Sadly no sign of support for EWS, but Evolution supports that.

Shame, it's not compatible with Thunderbird 102 (yet!?). Looks like a useful plugin.

Edit: From the github issues page: "I am working on an upgrade, ETA 2 weeks."

Works with plain IMAP, right? I do it this way (that is, access those mail services)

I just looked into that; it does, but only if my mail admin has enabled it :(

You can bypass that with running a local instance of davmail - https://github.com/mguessan/davmail

It works really well if you are comfortable on the command line to get it running.

ask it

I had to install TBSync and its Exchange provider. After that, everything worked perfectly, including calendar syncing.

https://addons.thunderbird.net/en-US/thunderbird/addon/tbsyn...

https://addons.thunderbird.net/en-US/thunderbird/addon/eas-4...

IMAP works out of the box with O365/Exchange and it supports oauth login which MS requires for most new accounts I believe. Calendar sync needs a plugin as far as I know.