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version 78 uncombatible with old mail servers

markku.tiuri
markku.tiuri
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I am using Windows 10 Desktop PC that I close for every night. We are using an OLD legacy mail-server that worked with old Thunderbird client 68 perfectly. I can not find the way to STOP Thunderbird client from updating to version 78 that does not work with legacy Mail server when I turn the PC on again. I have to reinstall the 68 version every time there is an update to Thunderbird , which happens several times a week.

I am using Windows 10 Desktop PC that I close for every night. We are using an OLD legacy mail-server that worked with old Thunderbird client 68 perfectly. I can not find the way to STOP Thunderbird client from updating to version 78 that does not work with legacy Mail server when I turn the PC on again. I have to reinstall the 68 version every time there is an update to Thunderbird , which happens several times a week.

Chosen solution

Version 78 changed the minimum level for TLS to TLSv1.2 Perhaps you have a problem with this and that's why 78 is not working for you. Suggest you allow update to 78 and then follow the information at the link to reset the minimum level of TLS and finally restart Thunderbird again. https://support.mozilla.org/en-US/kb/thunderbird-78-faq#w_how-to-enable-outdated-security-protocols-tls-1-0-and-1-1

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All Replies (2)

Toad-Hall
Toad-Hall
  • Top 10 Contributor
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Chosen Solution

Version 78 changed the minimum level for TLS to TLSv1.2 Perhaps you have a problem with this and that's why 78 is not working for you. Suggest you allow update to 78 and then follow the information at the link to reset the minimum level of TLS and finally restart Thunderbird again. https://support.mozilla.org/en-US/kb/thunderbird-78-faq#w_how-to-enable-outdated-security-protocols-tls-1-0-and-1-1

markku.tiuri
markku.tiuri Question owner
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Thanks Toad-Hall. Your suggestion of changing the TLS min level from default 3 to 1 helped immediately. The mail started coming as soon as the "Enter integer value" pop-up was closed.

The hardest trick was finding the "Config Editor" from Tools>Options>General and scrolling to the end of the page to find the last "Config Editor" button that opens the "about.config" pop-up. After that it is better to write into the search key field "security.tls" and click twice on the row "security.tls.version" to open the "Enter integer value" pop-up to change the default value 3 to 1 and press "ENTER" button.