This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

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 cavab
  • 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