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logging into the server is not possible. Probably an incorrect configuration, username or password

  • 5 replies
  • 1 has this problem
  • 4 views
  • Last reply by sfhowes

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One of my customers has an issue with Thunderbird, suddenly no e-mails came in while username and password were not changed.

With mailpv I got the username and password, I used these credentials to login on the providers webmail site and was able with these credentials to login and read my e-mails (also the latest ones).

I removed Thunderbird (uninstall) en removed the data in %APPDATA%\Thunderbird and reinstalled it again. Also the account was removed before uninstalling it.

While adding the account again I got the pop-up saying: "logging into the server is not possible. Probably an incorrect configuration, username or password"

The IMAP and SMTP server used where correct.

I also configured the standard Windows 10 e-mail program and that went successful but I did not get Thunderbird working again.

What could be wrong?

One of my customers has an issue with Thunderbird, suddenly no e-mails came in while username and password were not changed. With mailpv I got the username and password, I used these credentials to login on the providers webmail site and was able with these credentials to login and read my e-mails (also the latest ones). I removed Thunderbird (uninstall) en removed the data in %APPDATA%\Thunderbird and reinstalled it again. Also the account was removed before uninstalling it. While adding the account again I got the pop-up saying: "logging into the server is not possible. Probably an incorrect configuration, username or password" The IMAP and SMTP server used where correct. I also configured the standard Windows 10 e-mail program and that went successful but I did not get Thunderbird working again. What could be wrong?
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All Replies (5)

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Is there an antivirus such as Avast possibly interfering, or a VPN? The User Name should be the full email address, and the authentication on the smtp is the same as the incoming, normal password. It could also be due to the version of TLS on the server is not compatible with TB 78. Check that there aren't any obsolete passwords in Options/Privacy & Security/Passwords.

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There is a antivirus program called 'Eset Internet Security' but this is not the issue. It worked perfectly before. It does also works with the default e-mail program from Windows 10.

Is it also known when the version of none supported TLS has been changed? Because it worked on Friday 6th and didn't worked from Saturday the 7th.

KR

Johan
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ESET might have worked fine until TB or ESET updated. The best way to rule out antivirus is to run in Windows safe mode. The issue with TLS arrived when TB updated from 68 to 78. Check the update history in Options/General to see if an update occurred on the 7th.

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I understand what you are saying but the strange thing is, it works fine with the default e-mail program of WIndows . If it was Eset, it should work as well.

I can look at the release notes (if there is any) what has been changed.

KR.

Johan
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A security app can coexist with some mail clients but not others. It's always recommend to exclude the TB profile folder from AV scanning (leaving the real-time background scan in place) and to disable scanning of SSL connections.

https://www.thunderbird.net/en-US/thunderbird/78.4.1/releasenotes/