Certificates are issued by a certification authority, and like a driver’s license, can be revoked. A certificate is usually valid for a year, after which, the signer must renew, or get a new, signing certificate to establish identity.

If you do not want to purchase a digital certificate from a third-party certificate authority (CA), or if you want to digitally sign your document immediately, you can create your own digital certificate.

You'll only see those certificates that you've added to the keychain for your Mac OSX user account and those certificates that are valid for digital signing or encryption.

If you purchased a Microsoft 365 subscription from a third-party retailer, such as Amazon, Apple, Best Buy, or Google Play, please contact them directly to manage your subscription and billing.

Microsoft Intune delivers certificates automatically to Outlook for iOS. To obtain or renew your certificates, please follow the instructions in the notification or email you received from Company Portal.

Just sign in with a free Microsoft account or a Microsoft 365 work or school account. With a qualifying Microsoft 365 subscription, you'll also have access to premium features.

Certificates can be obtained by exporting a password-protected .pfx file from Microsoft Outlook and emailing these to yourself. Tap on the .pfx attachment to begin the certificate installation. You can contact your IT help desk for assistance.

The Signature Details dialog box displays certificate information such as the signer’s name in the Signing as box, and who issued the certificate. Open the file that contains the certificate you want to view.

Certificates are moved to the device via email. You will need to export a password-protected .pfx file, and email it to yourself. Then tap on that .pfx file to install it onto the device/Outlook mobile. The following image shows how manual certificate delivery works in iOS.

With Microsoft 365 on your iPhone and iPad, you can take your files on the go and be productive at work, on the road, or at home. Go to the App Store and download the Office mobile apps you want. The first time you open an app, sign in with the account you use to sign into Microsoft 365.