How to Send a Secure & Encrypted Email in Outlook

April 26, 2024
8 Minutes
Modified on:
April 26, 2024
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Emails are more than just messages—they are important containers of personal, professional, and sometimes even classified information. Protecting these digital letters has become paramount, especially as cyber threats become more sophisticated.

At its core, a secure email is encrypted or coded so that only the intended recipient can decode and read it. Think of it as sending a sealed envelope, where only the receiver has the key to unlock it.

When emails are not secured:

They can be intercepted and read by unwanted parties.
Sensitive information, like bank details or personal data, could fall into the wrong hands.
The sender's reputation might be at stake if confidential information is leaked.

In essence, sending a secure email ensures that your messages remain private, just as you intended.

How to Send a Secure & Encrypted Email in Outlook: A Step-by-Step Guide

Outlook, a flagship product from Microsoft, has integrated tools to send encrypted emails. 

Note: The features described below are available in some advanced paid plans.

Here’s how:

a. Enabling the Encryption Features in Outlook

Steps to Set Up S/MIME Encryption

1. First, ensure you have added the necessary certificate to your computer's keychain. With the signing certificate ready on your device, integrate it with Outlook.

2. Navigate to Settings

Click on the File tab.

Go to Options.

Choose Trust Center, then click on Trust Center Settings.

3. Email Security Settings

On the left side, click on Email Security.

In the "Encrypted email" section, select Settings.

Under "Certificates and Algorithms," hit Choose, then pick the S/MIME certificate.

Confirm by clicking OK.

Using the Microsoft 365 Message Encryption

Within the email draft, select Options.

Click on Encrypt. From the available options, select the appropriate encryption type, such as "Encrypt-Only" or "Do Not Forward."

The "Encrypt-Only" feature is exclusively available to Microsoft 365 Apps for enterprise users on Exchange Online. Microsoft 365 Message Encryption comes with the Office 365 Enterprise E3 license.

In your draft email, navigate to File > Properties > Security Settings, check "Encrypt message contents and attachments," compose your email, and click Send.

When you encrypt outgoing emails, composing and sending them remains unchanged. However, recipients should have your digital ID to decode and read your messages.

  • Click on the File tab.
  • Choose Options.
  • Click Trust Center, followed by Trust Center Settings.
  • In the "Email Security" section, check the box "Encrypt contents and attachments for outgoing messages."
  • To modify additional configurations or to pick a specific certificate, click on Settings.

b. Using Digital Signatures in Outlook

Digital signatures are an official stamp on your email, assuring the recipient that the email has indeed come from you and hasn't been tampered with.

Signing a Particular Email Digitally

  1. When composing a message, go to the Options tab and select the Sign Message from the Permission section.

If the Sign Message button isn't visible:

  1. Click on Options within the email.
  2. Under More Options, access the dialog box via the launcher in the bottom right corner.
  3. Navigate to Security Settings and tick the box for "Digitally sign this message."
  4. Confirm with OK and Close.
  5. If the Sign Message button still isn't visible, you may not have set up a digital ID for signing. To set one up:
  6. Head to File > Options > Trust Center.
  7. Inside the Microsoft Outlook Trust Center, navigate to Trust Center Settings > Email Security.
  8. Use the Import/Export option to integrate a digital ID from your computer, or choose Get Digital IDs to find providers offering suitable digital IDs.
  9. Once done, craft your message and hit send.

Digitally Sign Every Outgoing Email

  1. Visit File and select Options > Trust Center.
  2. In the Microsoft Outlook Trust Center, proceed to Trust Center Settings.
  3. On the Email Security tab, under Encrypted Mail, activate the "Add digital signature to outgoing messages" option.

Depending on availability, you may choose:

  1. "Send clear text signed message when sending signed messages" if you want the message to be readable by recipients without S/MIME security. This is usually activated by default.
  2. For verification that your signed message reached its intended recipient intact, choose "Request S/MIME receipt for all S/MIME signed messages". This notifies you about who opened the email and when.
  3. For advanced configurations, such as opting for a specific certificate, click on Settings.
  4. Confirm your choices by clicking OK for any open dialog.

Enhancing Email Security with Neo

Neo understands the critical role email plays in businesses, and that's why it has been crafted to offer advanced security measures that cater to the dynamic needs of modern enterprises.

Advanced Security Measures

Neo's commitment to ensuring the safety of its users is evident through its robust security features. With advanced anti-spam and anti-virus mechanisms, Neo works relentlessly to filter out malicious content and threats. This proactive approach ensures that users are shielded from potential vulnerabilities.

Two-factor authentication (2FA)

An additional layer of security, 2FA requires users to validate their identity through two separate methods before accessing their account. It's an effective way to ensure that even if passwords are compromised, unauthorized users can't access your email.

4 Tips for Better Email Security Practices

1. Software vulnerabilities are a hacker's paradise. Ensure you're regularly updating and patching your software, whether it's Neo, Outlook, or any other platform, to benefit from the latest security enhancements.
2. Phishing attempts are becoming increasingly sophisticated. Constantly scrutinize emails from unknown senders and never click on suspicious links. If an offer seems too good to be true, it probably is.
3. The strength of your password is your first line of defense. Use a combination of letters, numbers, and special characters. Avoid obvious choices like "password123" and change them periodically.
4. Platforms like Neo come equipped with advanced security measures, including 2FA. This extra layer ensures that even if your password gets compromised, access to your account remains restricted.


In an era where email breaches are unfortunately all too common, ensuring the security and efficacy of your email communications is non-negotiable. While Outlook provides a good starting point, integrating it with advanced platforms like Neo can elevate your email game. Neo doesn't just offer enhanced security—it reimagines the email experience, ensuring businesses can communicate more effectively, efficiently, and securely. Ultimately, a combination of tools, awareness, and good practices can make all the difference in maintaining robust email security.

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