Microsoft keeps an eye on your account to help prevent anybody that's not you from signing in to it. When we see a sign-in attempt from a strange place or device, we add a second layer of protection and then send you email and SMS alerts. This could happen if you sign in to your account while traveling, or you install a new app that signs in with your account. But it can also be someone else trying to sign in to your account without your permission.
We let you know about the unusual sign-in attempt two ways:
If you received an unusual activity notice while sending email in Outlook, see Unusual activity in Outlook for more info.
To unlock your account, follow the instructions on the sign-in screen by selecting where we can send you a security code. Once you receive the code, enter it at the prompt and you’ll be back into your account.
If you’re traveling and can’t access the email or phone that you have associated with your account, there are some things you can try:
You should review your recent sign-in activity to see where any unusual sign-in activity is occurring. If you find account activity that you know you didn't do, you can flag it on the recent activity page and we'll help you secure your account.
Article ID: 13967 - Last Review: 22 Jun 2016 - Revision: 15