KevinTheJedi
Are you sure you just don't have the attributes cached in the DB or something, I have tested this with a personal outlook.com and my work account but there is no difference.
Personal:
Work:
But anyway, making the attributes configurable solves this (and isn't it needed anyway for other OAuth providers).
Also I would still like to emphasize that in my opinion using the deprecated API with this is a bad idea. In couple months people kind of have to deal with this again. Easy future proof solution would be just making the API optional, since it just used to validate the email address which is not really needed for IMAP/POP/SMTP (I understand getting the users info is needed in other cases). Better solution would be to add support for Graph, which unfortunately requires another access token.
Of course that can be easily worked around (for example with a mockup API), but that's not very user friendly.