Does Thunderbird support SSL/TLS connection security on smtp.office365.com port 587 for sending emails?

Microsoft 365 and Office
1

I'm having issues with sending emails when I choose SSL/TLS as the connection security method. However, I can send emails without any problems when I opt for STARTTLS or no security at all.

2

Hey there,

It sounds like you’re running into some trouble with Thunderbird and SSL/TLS connection security on smtp.office365.com port 587. Don’t worry, I’m here to help you sort it out.

First, let’s get the basics out of the way. SSL/TLS is a crucial security feature you should be using. I understand you can send emails with no security or STARTTLS, but it’s not recommended to bypass security measures. SSL/TLS provides end-to-end encryption, ensuring your emails remain private and protected during transmission.

Now, let’s troubleshoot the issue with SSL/TLS:

  1. Check your Thunderbird Settings:

    • Open Thunderbird and go to Account Settings.
    • Select your Office 365 account.
    • Under Outgoing Server (SMTP), make sure it’s set to smtp.office365.com on port 587.
    • In Security Settings, select SSL/TLS as the connection security method.
    • Ensure Authentication is set to Normal Password.

  2. Certificate Verification:

    • Ensure Thunderbird trusts the root certificate issued by Microsoft. This might be the culprit. You can do this:
      • In Thunderbird, go to Edit > Preferences > Advanced > Certificates.
      • Click View Certificates.
      • Check if the Microsoft root certificate is listed under Authorities.
      • If it’s not, you might need to download and import the certificate manually.

  3. Firewall and Antivirus:

    • Firewalls and antivirus software might be blocking the SSL/TLS connection. Temporarily disable any firewall or antivirus software and see if it resolves the issue.

  4. Update Thunderbird:

    • Ensure you’re running the latest version of Thunderbird. Sometimes, updates can resolve compatibility issues.

If none of these steps resolve the problem, you might want to try using a different email client or contacting Office 365 support for more specific assistance.

Let me know if this helps you resolve the issue.