User Guide
Integrations
S/MIME for Email

S/MIME Email Security

Secure/Multipurpose Internet Mail Extensions (S/MIME) allows you to sign (prove identity) and encrypt (protect content) email messages.

Internal Use Only: TrustLab certificates are private. If you send signed emails to External Recipients (e.g., Gmail, Yahoo), they will see an "Untrusted/Invalid Signature" warning because they do not trust the TrustLab Root CA.

Use this for internal corporate communication only.

Setup Guide

Configure Microsoft Outlook

Supported Versions: Outlook 365, 2019, 2016.

1. Open Trust Center

Go to File > Options > Trust Center > Trust Center Settings.

2. Email Security

Select Email Security from the left sidebar.

3. Import Certificate

Under Encrypted Email, click Settings...

  • Signing Certificate: Click 'Choose' and select your TrustLab cert.
  • Encryption Certificate: Same as above.

4. Save

Click OK to apply.

Configure Thunderbird

Version Requirement: v115+ (Supernova) or newer.

1. Account Settings

Click the Menu (≡) button and select Account Settings.

2. End-to-End Encryption

Select your email account from the sidebar and click End-to-End Encryption.

3. Import Certificate

In the S/MIME section, click Add (or Manager) to import your .p12 file.

4. Apply Certificate

Under Select Certificate, choose the imported file for both:

  • Digital Signing
  • Encryption

How to Test

Send an email to a colleague who also has the Root CA installed. They should see a verified Ribbon/Badge icon indicating the email is trusted and unmodified.