When you need to protect the privacy of an email message, encrypt it. Encrypting an email message in Outlook means it’s converted from readable plain text into scrambled ciphertext. Only the recipient can decipher the message for reading. Any other recipient sees indecipherable text. Outlook supports Message Encryption (Information Rights Management).

When to use Encryption in email?

Email encryption should be used when sending sensitive data* to external parties outside of your email system.

Encrypt with Microsoft 365 Message Encryption

Windows: 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.

Mac: In an email message, choose Draft from the menu bar, select Encrypt, and pick the encryption that has the restrictions you want to enforce, such as Encrypt-Only or Do Not Forward.

Image examples of both Microsoft Windows & Apple macOS below

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

  1. In the message that you are composing, click File > Properties.
  2. Click Security Settings, and then select the Encrypt message contents and attachments checkbox.
  3. Compose your message, and then click Send.

With the new Office updates, there have been some changes.

Examples of sensitive data

Sensitive information includes all data, whether original or copied, which contains:

  • Personal information (PII)
  • Protected Health Information (PHI)
  • Customer information
  • Employee Data
  • Confidential information – Intellectual Property & Trade Secrets
  • Operational & Inventory Information