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Thunderbird Version 140.7.1esr, Build ID 20260123195141 User Agent Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 OS Linux 6.1.0-33-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.133-1 (2025-04-10) OS Theme Xfce / Adwaita Application Binary /usr/lib/thunderbird/thunderbird-bin

Having a problem with an ATT POP account. TB stopped getting mail. After a minute and a half or so (wish it would time-out faster), I get a pop-up box in the top right of the screen that states: "Connection to server inbound.att.net timed out" and then quickly goes away.

Deleted passwords and cannot see where to create them again, as it never prompts me for new ones.

Thanks.

I believe since your last update, every time my phone switches a data provider, meaning goes from cellular data to my Wi-Fi or vice versa. Or if you go to airplane mode and then come out of it I get the Gmail authentication error. Every single time. I'm running Samsung Galaxy s23 running the latest version of Android 16. Has anyone else had this issue? I find it hard to believe that I would be the only one. It's getting really annoying having to keep clearing it or going in and then when you go into go through the settings it tells you it doesn't work. Any help would be appreciated.

My local network is 10.10.10.x and I can't log into my NAS, web server or another computer on the local network... Internet access is fine. Happens on Wi-Fi or Ethernet.

If I access the same web address using Safari or Chrome it works just fine and it used to work before the software update to the 147 build.

So what switch/setting got kicked over during the upgrade that I have to turn off?

These kind of issues really make me mad at the Firefox Dev team... and I'm a very long time user.

Hi, i installed Thunderbird on macOS and it worked until yesterday. Today it continue to fail connection with the google server. I tried restarting computer and close/reopen Thunderbird but nothing is working. I also tried to limit connections from 5 to 3, and nothing happened. Can you help me ? I don't have network problems.

I have got two e-mail by Thunderbird : X@orange => OK but X@kohinos.net NO connection Thunderbird said : connection time exceeded'. What to do?

(PII removed by moderator)

This just started 4 or 5 days ago ( 2026.1.23 ish). I did not update TB nor make any changes to the account in question (that I'm aware of). The errors show up every few minutes, with a 'beep' sound and notification pop-up showing up each time - is very annoying.

I was running v145 when it started. I saw there was an update to 147 and installed that; same issue. I restarted TB into Troubleshooting mode and am still getting the error.

This is running on MacOS 15.7.3. Hardware is MacMini (2024) with Apple M4 chip.

Generally I still seem able to received & send emails.

I opened Activity Manager and Error Console. Error console doesn't seem to have much (using 'Multiprocess', with Errors, Warnings, Logs, Debug enabled). Activity manager shows things such as:

<my account name>

   Connection to server outlook.office365.com was interrupted.    09:49
   Failed to connect to server outlook.office365.com.    09:52
   Authentication failure while connecting to server outlook.office365.com.    09:58
   Authentication failure while connecting to server outlook.office365.com.    10:03
   Connection to server outlook.office365.com was interrupted.    10:10
   Connection to server outlook.office365.com was interrupted.    10:14
   Connection to server outlook.office365.com was interrupted.    10:20

There was an error or log entry that I was able to find a few days ago that made me think it was Calendar related, but now I'm not finding that message.

I am running Thunderbird 147.0.1 (64-bit) on Windows 11 Pro 25H2. I have Thunderbird set up with two email accounts -- gmail and outlook.com (an old msn.com address). Approximately every 10-14 days the msn.com account encounters an error with the message "Command Error 12." When this happens, Thunderbird immediately drops all the local email folders for the msn.com account, and attempts to redownload all email and folders associated with the account. The msn.com account in question is configured for IMAP:

server name: outlook.office365.com Port:993 Connection Security: SSL/TLS Authentication Method: OAuth2

The expected behavior here would be for Thunderbird to display a connectivity error message but retain all local email on my laptop. However, this specific connectivity issue is dropping all locally stored email. I also noticed that the mail columns get reset to default. It appears this issue is causing Thunderbird to delete not just the email but some of the account configs as well.

At present, I do not have a screenshot showing the command error 12 message. I will try to take a screenshot the next time the issue occurs. What is not clear is whether this is an account setup issue or a bug in Thunderbird. Any advice would be appreciated. Thanks.

Hi, When I click on a link in ANY email, it says " Hmm. We’re having trouble finding that site. We can’t connect to the server at omxj86ebb.cc.rs6.net. If you entered the right address, you can:

   Try again later
   Check your network connection
   Check that Firefox has permission to access the web (you might be connected but behind a firewall)

I know I did something to make my computer more secure, but don't remember. Please help! THANK YOU!

In initial set up of Thunderbird laptop: on the last screen of set up, after entering username and password, Thunderbird set up posts a green background notice: " [checkmark] Configuration found in Mozilla ISP database." When "Done" is selected, a the following yellow background notice is posted: "Unable to log in at server. Probably wrong configuration, username or password." I know username and password are correct; they allow access to email via Spectrum webmail. I am confident configuration is correct [IMAP] \,because that is the configuration I have always used with my Thunderbird account on other computers. Suggestions?

The last few days I am unable to load websites that I regularly use. I get a cannot find error message. I have no clue what is going on. I turned off the vpn but that had no effect. This is really hindering my getting things done. Anyone with insight? I cleared the cash and cookies and all that, rebooted the browser as well as the desktop. Thanks

I am setting up a new computer with Linux Mint and Thunderbird. I got my primary comcast.net account added in and working but when trying to add another account I get the following:

Unable to connect

The connection was refused when attempting to contact localhost.

   The site could be temporarily unavailable or too busy. Try again in a few moments.
   If you are unable to load any pages, check your computer’s network connection.
   If your computer or network is protected by a firewall or proxy, make sure that Thunderbird is permitted to access the web.

Since the first account works, I assume there is no problem with network connection, firewalls, or proxy settings. I have confirmed spellings of username and password. Any ideas?

A search showed that others have experienced this same error message, but as far as I can tell, they all were unable to access their email. These messages began appearing about a month ago. They pop up in Troubleshooting Mode. They did not in Windows Safe Mode. AVG and ZoneAlarm are not the culprits.

Greetings.

For many years I have used Thunderbird to send and receive mail through my Outlook account (while happily donating to Mozilla).

A few months ago, every initial attempt to send a message abruptly started to fail, generating the dreaded notice that “the message could not be sent because the connection to Outgoing server (SMTP) smtp-mail.outlook.com timed out.”

What is odd is that if I keep trying to send, the message always goes out eventually -- sometimes after only two tries, sometimes after ten tries.

Thus, my Outlook account works, my Thunderbird settings work, the SMTP server works -- but only at random intervals.

The problem has continued through several Thunderbird updates, including the current one (147.0.1). I tried changing the server to smtp.office365.com and got the same performance.

I am on MacOS 15.4 and am not running any third-party antivirus or firewall product.

My thanks to anyone who has insight into this problem.