Back to Documentation
Microsoft Office 365

How to Send Secure Email in Outlook (End User Guide)

Overview

This document explains how to send secure email in Microsoft Outlook using built-in encryption options such as Microsoft 365 Message Encryption and S/MIME.

Secure email ensures that only the intended recipient can read the message and attachments.

Supported Encryption Methods

Outlook supports:

  • Microsoft 365 Message Encryption (OME)
  • S/MIME (certificate-based encryption)
  • Information Rights Management (IRM)

Your available options depend on your organization’s configuration.

How to Send an Encrypted Email in Outlook Desktop

Step 1: Create a New Email

  1. Open Outlook.
  2. Click New Email.
  3. Enter recipient, subject, and message.
  4. Attach files if required.

Step 2: Apply Encryption

  1. Click the Options tab.
  2. Select Encrypt.
  3. Choose one of the following:
  • Encrypt Only
  • Do Not Forward
  • Sensitivity label (if available)

Step 3: Send the Email

Click Send.

  • Internal recipients may open it directly.
  • External recipients may authenticate via a secure portal or one-time passcode.

How to Send an Encrypted Email in Outlook Web (OWA)

  1. Click New Message.
  2. Select the lock icon.
  3. Choose your encryption option.
  4. Send the email.

Frequently Asked Questions

How do I send a password protected email in Outlook?

Outlook does not use static passwords. Select Encrypt before sending. External users may receive a one-time verification code.

Is Outlook encrypted by default?

Outlook uses TLS encryption in transit. Message-level encryption must be manually applied or enforced by policy.

Can I recall a secure email?

Recall is only possible within the same Exchange organization and is not guaranteed.