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 It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired.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 ...

Select Edit contact, and then select Save & Close. View a certificate for a contact On the Navigation bar, select People. Select the person's name, and then on the Contact tab, select Certificates. Digitally sign a single message in classic Outlook In the message, on the Options tab, in the Encrypt group, select Sign.

See how to view the details for signatures and certificates.

Xbox Support ... Xbox Support

Summary Email signatures create professional consistency across your business communications and ensure recipients have your contact information in every message.

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

Want to add a padlock to your email messages? You can use encryption and digital signatures in new Outlook, classic Outlook, and Outlook on the web for work or school accounts to increase the security of messages. Encrypting an email message in Outlook means it's converted from readable plain text into scrambled cipher text. Only the recipient who has the private key that matches the public ...

To learn about digital signatures (also known as digital ID), what they can be used for, and how to use them in Word, Excel, and PowerPoint, see All about digital signatures. Create a signature line in Word or Excel (desktop) In the document or worksheet, place your pointer where you want to create a signature line. On the Insert tab, select Add a Signature Line in the Text group. In the ...

Careers About Microsoft Company news Privacy at Microsoft Investors Diversity and inclusion Accessibility Sustainability English (United States) Your Privacy Choices Consumer Health Privacy Sitemap Contact Microsoft Privacy Terms of use Trademarks Safety & eco Recycling About our ads © Microsoft 2026

Use a ready signature template from a gallery to create your email signature in Outlook.