Step 1. Login to https://outlook.live.com
Step 6. Verify your account (if necessary).
You may be asked to verify your account if you are using a browser you don't normally use. Microsoft will send a code to your backup email address.
Scroll down and view the list of activities. If you see any suspicious activity such as “Successful Sign-In” from a location that you think is not your’s, then it’s high time you increase the security of your email account.