Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

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
Locked

Errors

SuMo Bot

Almost anything I try to do with Thunderbird, even replying to emails requesting advice, I come up with errors, such as:

Sorry, you have been blocked

You are unable to access thunderbird.net

upstream request timeout

upstream connect error or disconnect/reset before headers. reset reason: connection termination

Almost anything I try to do with Thunderbird, even replying to emails requesting advice, I come up with errors, such as: Sorry, you have been blocked You are unable to access thunderbird.net upstream request timeout upstream connect error or disconnect/reset before headers. reset reason: connection termination

All Replies (3)

- What is your operating system?

- What version of Thunderbird?

- Who is your email provider?

- What Anti-virus or other network security program do you use, if any?

- Please quote all error messages you see, precisely and in full. Screen shots would suffice.

Windows 11 Thunderbird 155.0.1 (64-bit) I have Spectrum email (a very old new.rr.com address) and gmail set up on Thunderbird. Avast

I can't remember what all I did to get those error messages. I had posted the error messages in my first message here.

I'm amazed I'm being able to post this reply right now! I'm not entirely sure but I think things are working a little better at the moment.

You should be aware that Spectrum/Charter/etc. has been having severe intermittent connectivity problems with many or most email clients for weeks. They seem to be unwilling or incapable of dealing with it. We are watching the situation closely and if we find anything that can improve the situation we will let everyone know. But for now the ball is in their court.

This is a web forum and access to it has nothing to do with the program Thunderbird, except that both it and your web browser connect to the Internet through Spectrum.

Also, thunderbird.net is where Thunderbird's installer program can be found. Normally, after the program is installed, Thunderbird never needs to visit that site again except for updates, so I wonder where that error message came from?.

Modified by Lin

This question has been locked because the original author has deleted their account. While you can no longer post new replies, the existing content remains available for reference.