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Thread: Thunderbird Version 78.4.3 Email Send fail warning.

  1. #1
    Crazy Diamond
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    Default Thunderbird Version 78.4.3 Email Send fail warning.

    Version 78.4.3, first offered to channel users on November 11, 2020 has a security change to email protocols which affects some pop3 email accounts.

    For me it was, yeah I know it's not the most secure mail server, however my wife & I still have a lot of older friends & family that use this address & it's almost beyond their ability to comprehend any change of address we would make.
    I personally usually use gmail most of the time.

    Any way back to the problem; after the latest update to Version 78.4.3 of Mozilla Thunderbird, the activ8 address would receive mail no problems but when trying to send you get a warning fail message.

    Sending of the message failed.
    Peer using unsupported version of security protocol.
    The configuration related to must be corrected.
    The reason is that the new TB version sets the security.tls.version.min to 3 & the security.tls.version.enable-deprecated = false.

    So the fix is to go to the Thunderbird Tools/Options scroll to the bottom & select 'Config Editor', say 'I accept' to the warning.
    Then scroll down & set security.tls.version.enable-deprecated = true, then security.tls.version.min to 1.
    Some email servers may get away with just the 'deprecated = true' change, but mine didn't.
    see image, double click the item to get the change, then close dialogue, job done.

    See details of what tls version means at>> .

    Hope that saves someone some time finding the reason for email failure in TB.

    Cheers, Tiny
    "You can lead a person to knowledge, but you can't make them think? If you're not part of the solution, you're part of the problem.
    The information is out there; you just have to let it in."

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