It was a similar story at Microsoft: for a long time we couldn't reliably use @microsoft.com e-mail addresses as MSAs ("Microsoft Accounts", the then-new name f

It was a similar story at Microsoft: for a long time we couldn't reliably use @microsoft.com e-mail addresses as MSAs ("Microsoft Accounts", the then-new name for Windows Live IDs), so we were all told to create a new non-@microsoft.com address for stuff that needed an MSA - I don't remember the guidance for if we could re-use our pre-existing personal addresses or not but I know that some people did, but most people created new @outlook.com addresses. IIRC, they did iron out the problems eventually, and finally came-up with a semi-decent UX for normal (non-MSFT) people that had an Office 365 ("Organizational account") with the same e-mail address as an MSA - but I think internal MSFT accounts still have issues? My information isn't up-to-date fwiw. FWIW, I never had access to any "real" internal resources via my new @outlook.com MSA address - the only things it did have access to was things like MSDN Subscriber Downloads[1] and as a backup/recovery e-mail address for my @ms org account. [1]: Oddly enough, I retained access to the MSDN Subscriber Downloads area, including full ISOs and Product Keys for about 2 years after I left the company, I only lost access because that was when they moved everything over from "MSDN Subscriber Downloads" to "My Visual Studio" which changed everything.