Send digitally signed messages as clear text if you want to make sure that your digitally signed messages can be opened by all recipients, even if they do not have an S/MIME mail application and can't verify the certificate.

You can add signatures manually to individual email messages, or you can have a signature automatically added to every message that you send. In Outlook, multiple objects must be anchored before you can drag them all at once.

Open the digitally signed message. Look at the Signed By status line to check the email address of the person who signed the message. It isn't enough to check the email address in the From line—you want to verify who actually signed the message, not only who sent the message.

You can change the default signature that automatically appends to every email you send. You can also update an existing email signature. Here's how: On the Outlook menu, click Settings. Under Email, click Signatures.

If you want to insert a digital signature into an email, you need to install a digital ID (certificate), which is verified by a third party. Before you can send and receive messages with encryption or digital signatures, or digital IDs, please follow the instructions to set up encryption in Outlook.

Your digital signature, which includes your certificate and public key, originates from your digital ID. And that digital ID serves as your unique digital mark and signals the recipient that the content hasn't been altered in transit.

View all your Microsoft 365 Groups in Mail and Calendar views. In Mail, Groups are located under the Groups node for your account. In Calendar, Groups are located below your calendar folders. Nested compose in the Reading Pane. Reply to messages without opening a new compose window.

Click the certificate that you want, and then click View Certificate. In the email message, click or on the Signed By line. Click Details. Click Signer or Encryption Layer, and then click View Details. To see details about the certificate, click View Certificate.

To report issues or provide feedback, simply go to Help > Contact Support in Outlook for Mac. For more information, see Contact Support in Outlook for Mac. Have a feature request? To suggest new features in Outlook for Mac, go to Help > Give Feedback. We're listening.

Whether it’s a new job title (congratulations!) or a phone number change, make sure you keep your email message signature up-to-date. If you're using new Outlook, for more information about email signatures, or if you haven’t created one yet, see Add a signature to messages.