Sending, receiving, and organizing email in Outlook.com
I am having the same issue.
I cannot open a draft email or try to compose a new one or the whole browser page just refreshes multiple times then I'm back looking at my inbox again.
I see a bunch of CORS ajax errors and we are using the Microsoft hosted Outlook so there is nothing we can do here.
The calls are so aggressive I'm even seeing rate limit responses from the server on top of an array of various 4xx status codes.
I see these errors happening a bunch trying to call https://outlook.office365.com/autodiscover/autodiscover.json/v1.0/{email_address}?Protocol=ToDo
The error notes a CORS error from origin https://outlook.office.com which is very much a Microsoft issue and is causing users to be completely unable to use Outlook.
Maybe Microsoft should actually test releases and not just give vague crappy responses to support questions....