Whenever you sign in to your Microsoft account, you may also get sign-in approval notifications in the Outlook mobile app. You will see sign-in requests appear either on the lock screen or in the Outlook mobile app. You'll also be able to get one-time passcodes, which you can copy/paste into other sign-in screens.

If you can't sign into your Microsoft account, use the sign-in helper to identify the problem. How to use the Microsoft account sign-in helper The tool will ask you to enter the email address or mobile phone number you're trying to sign in with and check the details you provide. If it detects a problem with your account, we'll tell you what you need to do to solve the problem. If the tool ...

Use your Microsoft account to sign in to Microsoft services like Windows, Microsoft 365, OneDrive, Skype, Outlook, and Xbox Live.

Certificate authority (CA) A certificate authority is an entity similar to a notary public. It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired. Top of Page Digital signature assurances The following terms and definitions show what assurances are provided by digital signatures. Authenticity The signer is ...

About digital signatures and certificates in Office, and buying a digital certificate from a certificate authority or create your own.

Provides information for avoiding and reporting Microsoft technical support scams.

Add a contact from a profile card for someone in your organization If you're using Outlook in an organization and you select someone's name or picture in Outlook or other Office apps and services, you might get their profile card with more information. From their profile card, you can select Add to contacts, then you can add more information like address, personal phone, or notes. The ...

How to create or edit your Outlook signature for email messages. Include your signature, text, images, electronic business card, and logo.

Learn how to add all your different accounts to the Microsoft Authenticator app.

My username and password have stopped working If you can't sign in with a correct password If your username or password have stopped working, you may need recover your account: Select Recover your account below and type in the email address, phone number or Skype name you use to sign in.