The mailbox received a Microsoft one-time code.

Receiving Microsoft one-time code in email is double authentication. Two-factor authentication (sometimes called two-factor authentication) helps protect Microsoft accounts by making it more difficult for others to log in. Use two different forms of identification: password and contact information (also known as security information). Even if others find the password, they will be forced to stop if they can't access the security information. This is why it is important to use different passwords for all accounts. If you enable two-factor authentication, an email, mobile phone or authenticator application will receive a security code every time you log on to an untrusted device. When two-factor authentication is turned off, you can only use the security code to periodically verify your identity when the security of your account is threatened. Two-factor authentication starts with an email address (it is recommended to use two different email addresses, one for common use and one for backup), a phone number or any verification procedure. When logging in on a new device or from a new location, the security code entered on the login page will be sent to the user. E-mail (E-mail for short) is a communication method that provides information exchange by electronic means, and it is also one of the most commonly used functions of the Internet. It was invented by RayTomlinson in the autumn of 197 1. E-mail can be text, image, sound and other forms, and can be sent to people with e-mail addresses all over the world in a few seconds to a few minutes. Network users can write letters, send and receive letters through electronic communication systems. It is convenient to use, fast to transmit, low in charge, easy to preserve and unimpeded in the world, which greatly facilitates communication and exchanges between people and promotes social development.