Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hi dBelcourt,
Thank you for posting your concern here at the Microsoft Community Forum.
We see that you received a notification that there was an unusual activity on your account. Yes, that email was from our system, and it is a legitimate Microsoft Account notification.
For your account's safety and security, every Microsoft Account has a feature that can detect if your account is being accessed outside of your usual sign in location. If you do not recognize the sign in attempt, we highly recommend that you change your password immediately. This will protect your account from being hacked.
In addition, we recommend that you consider adding an extra layer of security to your account. Here's how you can protect your Microsoft Account: How to help keep your Microsoft account safe and secure.
If you use a VPN connection, the system will detect that and it will continue to notify you of the unusual activity. If this is the case, you'll need to add your device as trusted to make sure that you won't be locked out, and keep all your security information (phone number and alternate email address) updated.
Let us know if you have additional queries.