For information about how to request a digital certificate from a certification authority, see Find digital ID or digital signature services and Mac Help. You must also have a copy of each recipient's certificate saved with the contacts' entries in Outlook.

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.

When you send a digitally-signed macro or document, you also send your certificate and public key. Certificates are issued by a certification authority, and like a driver’s license, can be revoked.

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.

Because S/MIME receipt requests must include a digital signature, you must Set up Outlook to use encryption and digital signatures to request an S/MIME receipt.

If you plan to exchange digitally-signed documents together with other people, and you want the recipients of your documents to be able to verify the authenticity of your digital signature, you can obtain a digital certificate from a reputable third-party certificate authority (CA).

Open the Outlook for iOS app on your iOS device. At the top of the app, tap the Outlook button next to Inbox, and then select Settings . Select Account, then Add Account to add one of your existing email accounts, or Create New Account if you want to create a new Microsoft account.

Go to the Apple ID website in a web browser and enter your Apple ID and password. If you already turned on two-factor authentication, you'll receive a code on one of your trusted devices. Enter this code to continue. Otherwise, turn on two-factor authentication.

To see details about the certificate, click View Certificate. The email encryption certificate details for the messages that you send or receive can be reviewed.

All you have to do is get the template, copy the signature you like into your email message and personalize it to make your own Outlook signature. Check out the video to see how it's done.