Important Notice: We're experiencing email notification issues. If you've posted a question in the community forums recently, please check your profile manually for responses while we're working to fix this.

On Monday the 3rd of March, around 5pm UTC (9am PT) users may experience a brief period of downtime while one of our underlying services is under maintenance.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Thunderbird only uses TLSv1 regardless of security.tls.version.min/max Settings

  • 1 reply
  • 1 has this problem
  • 2 views
  • Last reply by Mortimer

more options

Versions: Thunderbird 68 and 78, Windows 10

The admin disables TLSv1 at the mail server and with both thunderbird versions fetching and sending mail causes a TLS negotiation error. SSL/TLS or STARTTLS, any authtentification method: All combinations do not work.

The security config ist by default, meaning security.tls.version.min = 3 and security.tls.version.max = 4. But if i monitor the connection with wireshark always the connection is TLSv1 is used, even if i modify the security.tls settings.

What can i do to force thunderbird to use more newer TLS versions?

Versions: Thunderbird 68 and 78, Windows 10 The admin disables TLSv1 at the mail server and with both thunderbird versions fetching and sending mail causes a TLS negotiation error. SSL/TLS or STARTTLS, any authtentification method: All combinations do not work. The security config ist by default, meaning security.tls.version.min = 3 and security.tls.version.max = 4. But if i monitor the connection with wireshark always the connection is TLSv1 is used, even if i modify the security.tls settings. What can i do to force thunderbird to use more newer TLS versions?

All Replies (1)

more options

Solution was found:

The admin changed the TLS cipher suites at the mail server after calling him. After that Thunderbird uses automatically TLSv1.2.

Modified by Mortimer