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).

A digital signature on an e-mail message helps the recipient verify that you are the authentic sender and not an impostor. To use digital signatures, both the sender and recipient must have a mail application that supports the same encryption type.

A digital signature is an electronic, encrypted, stamp of authentication on digital information such as email messages, macros, or electronic documents. A signature confirms that the information originated from the signer and has not been altered.

To create an e-sign request, you’ll need to sign into your account with an available e-signature provider such as Adobe Sign or DocuSign. If you don't have account, it's easy to start a free trial or create an account.

Before activating and if you haven't already, you'll need to redeem and install Office on your PC or Mac. In the top menu bar select Finder > Applications and scroll down to the Microsoft Office apps. Open any Office app, like Microsoft Word and in the What's New box that opens, select Get Started.

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.

If you don't see the Sign Message button, you might not have a digital ID configured to digitally sign messages, and you need to do the following to install a digital signature.

When a user signs in to any of the Microsoft 365 apps for iOS or Mac, the user enters their user name and password on the sign-in page and the sign-in page reappears and prompts the user for their user name and password again. This problem can occur if you're using an AD FS 2.0 server that's missing critical updates.

Sign in to your work or school account, and then select Sign in. Complete the rest of the registration process, including approving your identity verification request (if you use two-step verification) and setting up Windows Hello (if necessary).

When you add a digital signature to a Microsoft Office InfoPath 2007 form, the signature is invalidated if the information is changed by anyone but you. This article describes how to add a digital signature to an Office InfoPath 2007 browser-enabled form that is designed to accept it.