Protecting company or organizational data is extremely important. One solution for protecting message content is Secure/Multipurpose Internet Mail Extension (S/MIME). Mobile messaging applications like Outlook for iOS and Android work in conjunction with S/MIME to sign and encrypt Microsoft 365 message data.
S/MIME provides encryption, which protects the content of e-mail messages, and it provides digital signatures, which verify the identity of the sender of an email message. S/MIME in Outlook for iOS and Android is supported with Microsoft 365 accounts using the native Microsoft sync technology.
More information can be found at S/Mime for Outlook for iOS and Android.