Email Encryption for Microsoft Office365 Outlook Users

Encrypt with Microsoft 365 Message Encryption
If you are a Microsoft 365 subscriber:
In an email message, choose Options, select Encrypt and pick the encryption that has the restrictions you want to enforce, such as Encrypt-Only or Do Not Forward.
Encrypt button options
Note: Microsoft 365 Message Encryption is part of the Office 365 Enterprise E3 license. Additionally, the Encrypt-Only feature (the option under the Encrypt button) is only enabled for subscribers (Microsoft 365 Apps for enterprise users) that also use Exchange Online.
For Outlook 2019 and 2016,
In an email message, select Options--Permissions and pick the encryption option that has the restrictions you'd like to enforce, such as Do Not Forward.
Encrypt a single message
In message that you are composing, click File--Properties.
Click Security Settings, and then select the Encrypt message contents and attachments check box.
Compose your message, and then click Send.
Encrypt all outgoing messages
When you choose to encrypt all outgoing messages by default, you can write and send messages the same as with any other messages, but all potential recipients must have your digital ID to decode or view your messages.
On the File tab. choose Options--Trust Center--Trust Center Settings.
On the Email Security tab, under Encrypted email, select the Encrypt contents and attachments for outgoing messages check box.
To change additional settings, such as choosing a specific certificate to use, click Settings.

Music in this video:
Song: Lingus
Artist: OneWorld
Album: Juicy Ibiza 2014
Licensed to YouTube by: [Merlin] Black Hole Recordings (on behalf of Black Hole Recordings); BMG Rights Management (US), LLC, and 6 Music Rights Societies