I am registered user after the last update I can see two similar kinds of account: Microsoft 365 and Microsoft Exchange. What is the use case for them? I think I have my business account on Microsoft 365, I can read messages online via URL Outlook. Thus, which kind of account I have to setup to be able to read my emails?
Microsoft Exchange is the same as always, basic authentication and so on.
Microsoft 365 ins the new fancy one (just released) with OAuth.
Presumably the new one, but why not just try?
Especially if the old one stopped working or you have received warnings to that effect.