Data Protection Issues

How to Send a Secure or Encrypted Email in Outlook

Phi Hung Vo Oct 10, 2026 870 views

Question details

The user needs to know how to encrypt an email message in Outlook to ensure only authorized recipients can read the contents.

How to Send a Secure or Encrypted Email in Outlook

Product: Microsoft Outlook
Device & OS: not provided
Scenario: Sending sensitive information via email that requires encryption for data protection.
Observed behavior: The user wants to find the specific settings or entry points within Outlook to convert readable email text into cipher text before sending.

Before you start

Ensure that you have a Microsoft 365 subscription or an email account configured with an S/MIME certificate, as standard email accounts may not support built-in encryption.

Solution 1Recommended

Encrypt an Email Message Using Built-in Options

Use Outlook's native encryption features to convert your message into cipher text, securing it from unauthorized access.

Encryption converts your readable text into cipher text. Only a recipient with the matching private key or an authorized Microsoft account can decrypt and read the message, ensuring your sensitive data remains protected in transit.

Compose a new email

Launch Microsoft Outlook and click on the 'New Email' button to start drafting your message.

Open the Options tab

In the new message window, navigate to the 'Options' tab located on the top ribbon menu.

Enable encryption

Click the 'Encrypt' button. In some older versions of Outlook, this button may be labeled 'Permissions'.

Select encryption level

Choose the desired encryption restriction from the drop-down list, such as 'Encrypt-Only' or 'Do Not Forward'.

Send the secure message

Finish composing your email, attach any necessary files, and click 'Send'.

Encrypt an Email Message Using Built-in Options

S/MIME Requirements: If you are utilizing S/MIME encryption rather than Microsoft 365 Message Encryption, both you and the recipient must have valid digital certificates installed.

Free Microsoft Office alternative

Protect Your Documents Before Emailing with WPS Office

While Outlook manages your encrypted emails, you can add an extra layer of security by password-protecting your files before attaching them. WPS Office is a lightweight, feature-rich suite that allows you to easily encrypt Word, Excel, and PDF files, offering an excellent free alternative to Microsoft Office.

1. Download WPS Office: Visit the official WPS website to download and install the free office suite on your device.
2. Open your document: Launch WPS Office and open the document, spreadsheet, or presentation you wish to protect.
3. Apply a password: Navigate to the Menu, select Document Encryption, and set a secure password before attaching the file to your Outlook email.

Built-in document encryption to password-protect sensitive files before sending them via email.Fully compatible with Microsoft Word, Excel, and PowerPoint formats (.docx, .xlsx, .pptx).Free to use, lightweight, and features a familiar user interface for a seamless migration.

microsoft office alternative - wps office

Frequently Asked Questions

Can recipients without Outlook open an encrypted email?

Yes. If you use Microsoft 365 Message Encryption (OME), recipients using Gmail, Yahoo, or other email clients will receive a link to securely sign in or use a one-time passcode to view the message in a web browser.

Why is the Encrypt button missing in my Outlook?

The Encrypt button may be missing if your email account or subscription plan does not support encryption. Standard IMAP/POP accounts without an S/MIME certificate or an enterprise Microsoft 365 plan will not display this option.

How do I open an encrypted email sent to me?

If you are using Outlook with the authorized account, the email will typically decrypt and open automatically. If you are using a different email client, open the message and follow the instructions to authenticate via a one-time passcode or by signing into your account.

Microsoft Office Security Issues