I can tell you that using a VPN wasn't why your account was blocked. Most corporate employees connect to Outlook.com through corporate VPNs (both of my last employers required it).
I can tell you that using a VPN wasn't why your account was blocked. Most corporate employees connect to Outlook.com through corporate VPNs (both of my last employers required it).
I think it is just more likely MS doesn't know who you are yet. For example, if you're talking about how you get more captcha to fill out, I think this is because your IP address doesn't have the history to build reputation as you with MS.
I use mullvad and have used other vpns all the time with zero difficulty. The only service I can't use is netflix and even they let me access my account just fine I just can't actually play videos while connected to the vpn.
There is a huge difference between not allowing access to the service via vpn and banning an account by virtue of accessing the account from a legitimate vpn service. The latter is unusual it is not something anyone ought to expect from "every major service".
The latter is something I'd expect all the time, if I logged in to eBay from a M247 IP I'd expect the account to be suspended within minutes.