You may want to try using DavMail [1] for interfacing with Outlook. It is a reverse-proxy for email, so it talks to Outlook, and then mu4e can talk to DavMail directly.
How the hell did they break email? You need a browser with JS to log into your email server?
Isn't 2022 wonderful?
For instance, the Microsoft SMTP server in the cloud is picky about SSL/TLS protocols and ciphers.
Alas, in some orgs you will need permission to authenticate davmail to Outlook. My IT department has not approved davmail.
How can they tell?
Honest question because I fear my uni will start doing this out of “security “.
Office 365 requires SMTP/POP/IMAP to use an "xoauth" authentication scheme which relies on getting an authentication token from a web browser. The process of getting that token involves sending a request that includes an application ID.