Option 1: The following can be performed via Outlook Client or Outlook Web (outlook.office.com). Create an email and include one of the following keywords in the email subject or body, then send the email as normal:
Option 2: The following can only be performed via Outlook Client. Create an email, then follow these steps to encrypt your email.
Select Options > Permission. From the Dropdown select “Do Not Forward”. Then send the email as normal.
Option 3: The following can only be performed via Outlook Web (outlook.office.com).
The encrypt button is available in the ribbon when you’re composing a message. Select this before sending your email.