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i have a problem in the connection we need to have remote session

• Client : Mozilla Thunderbird (version utilisée) • Serveur SMTP : smtp-mail.outlook.com • Port : 587 • Sécurité : SSL/TLS • Authentification : OAuth2 • Message d’erreur exact indiquant un timeout / échec de connexion SMTP • Confirmation que : o le compte fonctionne en webmail o le service Microsoft est accessible o le problème persiste malgré un changement de réseau (si testé)

One of my two outlook email accounts no longer appears in Thunderbird, which says it is authenticated but not connected. This happened suddenly. I can still get the messages by going onto outlook.com. How do I get it back on Thunderbird?

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.

For 3 days now I have been unable to connect thunderbird to microsoft outlook. I have all the latest settings checked online with microsoft and it keeps failing... any suggestions on how to overcome this? Thanks

After system complete reinstallation Ubuntu 24.04 it is not possible to send mails with SMTP Server. Receiving messages is possible!! Two fault Messages happen, I've two SMTP servers: 1. No connection to SMTP possible 2. Server timeout

And yes, I've checked nearly everything what's to find in the internet, reinstallation, change and check settings and passwords, together with the specialist from my provider. Also my provider is not able to find a mistake. As I've found out in the net, there are sometimes problems to connect to SMTP, but no solution found. Is there some security in the UBUNTU system, which blocks the SMTP connection or is this a bug from Thunderbird? Thanks in advance Andreas

I have spent most of two days trying to Thunderbird to send email. It has worked perfectly for years. Suddenly, emails end up in Sent folder but go nowhere. My email host service sees nothing wrong. I can send emails through webmail and usually through Outlook. I have spent most of the day getting coached by Copilot and I am quite sure I have all the settings the way that worked flawlessly until two weeks ago. Is Thunderbird just dead and I need to go to Outlook?

For over a year, my browser occasionally loses connectivity. It may work for 3 hours or 3 days, but inevitably new tabs will stop working and then slowly the others will stop as well. When this happens, none of my other browsers are impacted. They work fine. It is only Firefox. The only solution is to close everything and lose all my work.

Once I do that and restart Firefox, I receive an error message telling me I am using an older version of Firefox that is not compatible with my profile. The only solution that brings me back to the best starting place is to re-install Firefox.

My company IT spent 3 days trying to find the problem and couldn't. I have uninstalled and reinstalled so many times. All extensions are turned off, as are the two add-ons. I have been using Firefox for over a decade and prefer it to all other browsers, but I need to find a solution or I am going to have to move on. Help!!!

My Thunderbird will not connect to the Comcast/Xfinity email account with the same settings that Outlook connected to and downloaded all my emails and my inbox structure. I believe this is either a battle between Comcast and Thunderbird or a big glitch in this application, My Gmail, Outlook365, work fine in Thunderbird, not Comcast. This started about a week ago. Has anyone found a solution?

As of this morning I am no longer able to download or send email via my Spectrum email account. A warning message appears next to the account name reading 'The certificate for mobile.charter.net:993 does not come from a trusted source.' The section from the View Certificate page makes it seem like the certificate should be valid:

Issuer Name

Country BE Organization GlobalSign nv-sa Common Name GlobalSign RSA OV SSL CA 2018 Validity Not Before Tue, 19 May 2026 11:45:30 GMT Not After Fri, 04 Dec 2026 11:45:30 GMT . Spectrum of course says it's an issue with my email client. Adding an exception for mobile.charter.net does work, but that doesn't seem like a good long-term solution. When I attemt to get a certificate for the server, I get a 'No Information Available - Unable to obtain identification status for this site'. I am not using a mail scanner and my only anti-virus is Windows 11 built-in Virus & Threat Protection. Any help or suggestions would be appreciated, thanks.

Hello,

I recently upgraded to a new PC from Windows 10 to Windows 11. For some reason I can not open links in any emails, even if right clicking them. I have gone through all steps here: http://kb.mozillazine.org/Standard_diagnostic_-_Thunderbird but nothing has changed. I have disabled Win Defender completely and still no change.

Any idea what I am missing? I am at a loss at this point.

Thanks for any advice or direction.

Why did retrieving messages suddenly stop. It was working yesterday and I made no changes to anything. I can send successfully. I am using Shaw/Rogers Pop server.

Why does "test connection to server" fail?

Hi there, it seems I'm suffering from the same problems as others in several countries. I have also not been able to access my gmx.com account via Thunderbird for about a week now. I live in Belgium and use a Proton VPN, in case this is relevant. I can't find how to delete cookies in history, nor any other potential solutions to the problem. Any help offered is greatly appreciated! Best, Doreen

Hello,

My father has a random issue with one of his email accounts. Context: Windows 11, TB 146.0.1. In TB, 5 mail accounts are configured, all IMAP, on 4 different providers.

All accounts work perfectly except the first one, which is also the default account. This account and the second account are both on my father's Internet provider. The configurations of both accounts seem identical (I checked more than once), except obviously for the name and password. On the first account (which is unfortunately the one my father uses most), connexion is often refused, and TB then asks to retry or enter a new password. Retry and reentering the password fail to solve the issue. When the connection to the first account fails, the second account (for the same provider) always works. Some time later (usually at least several days later), the first account will work again, without any obvious reason.

I tried exiting TB as well as clearing the cache, rebooting the computer, scanning for viruses, with no result.

I'd rather avoid re-creating the account in TB as this would change the order of the accounts, and my father (94 years old) might have difficulties to adapt to the change, but is someone can tell me how to recreate the account without changing the order, I am ready to try it.

I have a log of what happens when using only the "bad" account, and one for the good account from the same provider, but I don't know how to share them here. While creating the logs, I checked that if I set the second account as default (the first account having the issue before as well as after this), it still manages to connect. But of course, maybe the second account would have also had a connection issue later...

Does someone have any explanation, or ideas about how to solve this issue?

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.

Disconnect from home network repeatedly during the day. Have reinstalled, always on activated and allow in background. Nothing works. On my personal computer it never disconnect s

how do i delete or remove the message about could connect error

Contributor note: See also /questions/1576275 for the detailed error message.

I am using 140 ESR version on linux with Cloudflare's DNS over HTTPS and with DOH active for some reason resolving a domain like d3oklwo3y1bx83.cloudfront.net will resolve to local host IP 127.0.0.1.

I am using firefox about:networking#dnslookuptool to test resolution of the domain d3oklwo3y1bx83.cloudfront.net Both with DOH on and off the resolution remains local host. I tried another browser on the same workstation and I was able to receive a resolution of 13.225.193.203 13.225.193.133 13.225.193.64 13.225.193.58 Why is firefox ESR not able to resolve that domain? What are causes ?

Is is firefox dnslookuptool results.

For the past several days, TB has not been downloading messages from Yahoo. When I click to download, it will say "downloading message 1 of 36" and then time out.

I get this message when I double-click the progress bar: "Connection to server pop.mail.yahoo.com timed out."

The settings have not been altered in any way.

I've looked through the various discussions on similar questions in this community and on Reddit, but none of the suggestions have worked.

Help please.