As I was already complaining about #WUR I can add another nice episode from their IT:
As some of you might know, @thunderbird added native support for exchange. I immediately wanted to connect my uni-email and get rid of my wonky outlook-brave-webapp.
Of course, it did no go as expected: an error message told me that admin approval is needed.
So far so good, let's ask IT if they could change this, as thunderbird is the e-mail-clients with the oldest and best track record you could possibly have.

Reply from them: "We cannot provide access because we don't know what is done with the data gathered from your Office365 Account. You will need to use Microsoft Outlook."

in reply to Puntarella

Sorry for the delay! Thunderbird being a desktop client means the communication between the user's terminal and the organisation's mail server is direct without using a third-party server or a web application backend. It's probably best to point your IT department, for now, to our privacy policy to show what we do (and don't do!) with your data: thunderbird.net/en-US/privacy/