MAC Instructions
Start a new message.

You can add the Encryption button to your ribbon by click on the 3 dots and Customize Toolbar.

Click on Encryption and hold, drag to the toolbar and drop.

Start a new message, click on Encryption, please select one.

Windows Instructions
Start a new message. Then click on Options, Encryption drop-down menu.

Outlook onmicrosoft.com Instructions
Start a new message and click on Options.

The recipient will see this in their inbox
The recipient clicks on Read the message and a web page will open (could take up to 10 seconds to load the page)

Choose Sign in with One-time passcode, and you will receive a second email with the One-Time passcoe

They will see this message.

They will receive a passcode at the same email address (have them check Spam folder if they don't see it). Have them copy and paste.

Then the message will decrypt.