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I have been using Mozilla Thunderbird for decades and they have even contributed a small amount of money to Thunderbird periodically. Just within the last two or three days all of a sudden I have been unable to send emails with my phone. I receive emails, but I do not send them.

So I opened up a laptop where I did not have Thunderbird and set it up properly through Spectrum using the incoming and outgoing servers as mail.twc.com. and yes, just like on my phone. I continue to receive new emails, but even with the laptop I was unable to send an email.

I received the message"send message error sending a message failed. The message could not be sent because the connection to outgoing server smtp mail.twc.com was lost in the middle of the transaction. Try again."

I contacted Spectrum twice and both times they had me try to send a message through their Web server spectrum.net and that message did go through. Of course then their response is that this has to be a problem with the third-party app meaning Mozilla Thunderbird, and they can’t help with that at all. I sure would appreciate some help because I hate to walk away from Thunderbird as well as change my email address after all of these decades.

hi today thunderbird started showing yahoo popup login and after adding credentials i always get "something went wrong.We could not sign you in. Try again from a different device." Also popup once closed it opens instantly.

i can sign in normally from browser. thunderbird version is 147

is there any fix about this?

thanks for any help

regards

I’m currently facing a very frustrating issue with Firefox. I have been using Firefox for many years, and it is my favorite and most comfortable web browser for my day-to-day work. I rely on it heavily as all my bookmarks and other important details are saved there.

However, over the past few weeks, Firefox has been crashing more than 10 times a day. I have already tried all the troubleshooting steps available in the forums and through AI support, but none of them have resolved the issue. I also tried installing and using the Firefox Beta version, but the problem still persists.

In our environment, other users and devices are not experiencing this issue, so it does not appear to be related to internal firewall or antivirus restrictions.

Could you please help me troubleshoot this issue? I am attaching the error screen that appears after the crash along with the crash report for you

Since the up date my yahoo and AOL account want me to enter the password. When i do it is not accepted. It is correct since i tried it on a friends computer. I tried to use forgot password and it says I should enable java script and turn off ad blockers. I cannot do this in Firefox nor do I think it will help.

Hi!

I'm losing my mind by the fact that you can't hold to scroll or click to toggle scroll with MMB in Thunderbird, instead it opens a new tab which is completely useless to me since I share inbox and mail reader in one screen.

Is there any way to fix or change this?

If not I'd really like to request this as an option or feature.

Believe my T-bird account has somehow been corrupted. Takes forever to load on PC and always puts new emails in Trash folder. Often does not accept correct password. If I save / backup PROFILE, uninstall T-Bird and delete any Thunderbird folders on PC, if I restore per backup, will I be restoring the corrupted app. Don't want to loose email addresses, thousands of emails and email folder structure. Will a restore work? Thank you. Greg D

PS Version of T-Bird on laptop still puts all new email in Trash, but loads much more quickly, etc.

Hi

When Thunderbird is started maximized it overlap taskbar if is set to hide and taskbar won't show until Thunderbird is minimized and maximized. Another way is to press the Win key two times. Then the hided taskbar can be shown/use. The same thing happens to Firefox. Only when is first started. Then if Firefox is minimized and maximized, press Win key two times, press F11 two times then the hided taskbar show/hide normal.

It is a setting that can be changed to start Thunderbird and Firefox in full screen and do not overlap hided taskbar?

I apologize for the unhelpful summary line, but I am totally new to Thunderbird and the Unified Inbox is acting so strangely that I don't have any simple way to describe it.

Many (but not all) of the emails are displayed twice in the list of messages.

When I delete a message that isn't doubled, the message disappears from the inbox (as it should).

But when I delete one of the doubled messages ONE disappears as it should and on the other Thunderbird clears the From and Subject fields and changes the date to 12/31/1969, 19:00 -- the changed entry stays in the list and the body of the email is still shown in the lower pane. The only way I can get rid of the message is by selecting another folder (ANY other folder) then when I return to the Unified Inbox the deleted messages will be gone from the list.

I can't believe that this is how Thunderbird is supposed to work, so I assume I have something configured incorrectly (although nearly everything is still at the defaults that the installation gave me).

Can get(POP3), but can not send emails to a newly created personal outlook.com account.

the following error occurs when trying to send mail: Unable to authenticate to Outgoing server (SMTP) . Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)

all my setting are correct per thunderbird and microsoft:

  (smtp-mail.outlook.com, port 587,  STARTTLS, OAUTH2, xxxxx@outlook.com)

thunderbird error log file contains the following: . . . mailnews.smtp: S: 535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Mailbox. Visit https://aka.ms/smtp_auth_disabled for more information. [CH5P220CA0005.NAMP220.PROD.OUTLOOK.COM 2026-02-28T23:29:21.878Z 08DE7703D4D1982A]

SmtpClient.sys.mjs:452:17 mailnews.smtp: Command failed: 535 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Mailbox. Visit https://aka.ms/smtp_auth_disabled for more information. [CH5P220CA0005.NAMP220.PROD.OUTLOOK.COM 2026-02-28T23:29:21.878Z 08DE7703D4D1982A]; currentAction=_actionAUTH_XOAUTH2 SmtpClient.sys.mjs:578:19 mailnews.smtp: Error during AUTH XOAUTH2, sending empty response . . .

Based on my understanding its seems thunderbird is using SMTP AUTH instead of OAUTH2 as required for newer personal outlook.com accounts. Is my assessment correct? If so, is there a fix?

Normally, I can right click and tell Thunderbird that this is NOT junk, however, when I do this, these emails go back into the inbox and virtually instantly return to junk.

This is from anyone's email address that arrives from one particular website: @legacydigitalagency.com

I haven't come across this issue since I started using Thunderbird 20+ years ago.

Hi,

I'm looking to make Gmail my principal email account, instead of using my ISP account. Gmail requires 0Auth2 authentication, as many will know.

I'm a Luddite and prefer to use POP3, for a number of reasons. Thunderbird works fine (with POP3 Gmail), on my computer. Unfortunately, 0Auth2 doesn't appear as an authentication option, for POP3, in Tbird for Android. So the TB android app forces IMAP on my tablet and phone.

Is there any way around this? Are there any plans to incorporate 0Auth2 authentication for POP3 within Tbird for Android?

Thanks

I cannot seem to get Thunderbird to successfully connect to my email server on Network Solutions. Neither POP3 or IMAP works. I added an autoconfig of mail.<domain.ext>.netsolmail.net but this did not work. I am using the recommended ports and SSL/TLS settings. I can see from the Thunderbird Tools->Activity Manager that the connection is being refused. I can log into the mail account directly through the Network Solutions web access process. I used to just use a .forward on this account, but now I would like to set it up as my primary email server. Maybe there are other advanced settings on NS that need to be changed. Anyone know if there is something I am missing? I have changed the autodiscover to the autoconfig above in the CNAME and have map, mail, pop and smtp set to values recommended by NS. Do I need to add back the autodiscover setting perhaps? Many thanks for any suggestions.

I am using Firefox on Windows 11, in the process of switching from Chrome.

I run Cockpit (https://cockpit-project.org/) on web servers that I manage, and when I log into it on Firefox the screen flickers constantly, making it unusable.

There is no issue with any other web sites I have visited, and I can still use Cockpit when in Chrome. So ay suggestions on how to troubleshoot and resolve the issue with Cockpit and Firefox?

It appears how TB handles IMAP connections for outlook email accounts no longer works - OAuth2 connection flow broken, and this is likely due to stricter changes made on Microsoft's backend that is impacting connections going forward.

I have multiple email accounts configured and recently, I have been bombarded by login pop up - likely related to the OAuth2 authentic process.

Whilst I was able to circumvent the authentication process - i.e. not completing the flow process entirely as it expected, newly created outlook accounts appear to reveal two things:

1] There has been a recent change to the authentication process - i.e. the telling sign.

2] There is a now deeper issue when trying to connect outlook email accounts. It seems the reason why circumvention was possible with existing accounts was because they have already passed the OAuth2 process correctly - correct tokens exist. Since this won't be the case for new outlook accounts - no OAuth IMAP access token created, above error is given.

It seems the likely cause is because Thunderbird holds or requests a token that does not contain the correct IMAP audience/scope combination, and Exchange rejects it during SASL XOAUTH2 bind.

For your information, I am using the latest versions and able to configure Apple Mail client - which uses Exchange protocol (not IMAP), without issues.

I'm reading this> https://support.mozilla.org/en-US/kb/thunderbird-export#thunderbird:linux:tb148 Looks great but all of my messages sit on IMAP servers and I don´t need a backup of those. I _do_ need a backup of settings, passwords, pgp keys, to move to another workstation. It is unclear what exactly is exported.

Hello, I apologize, I am uncertain if this is the appropriate place to post this topic. I am having significant difficulty with the forum system when we require assistance.

I have been using Thunderbird for over a year now, and I have wanted to stop using it since the first month of use. Several times a month, I am unable to send messages even though I haven't made any changes. The message keeps popping up: “The message failed to send. The message could not be sent because the connection to the outgoing server (SMTP) ”server name" failed. The server may be unavailable or refusing SMTP connections. Please check that your outgoing server (SMTP) settings are correct and try again."

This is supposed to be my work email. I understand that ThunderBird is a volunteer platform. And that you do what you can, but I can't afford to be stuck like this for a “yes” or a “no.” You were highly recommended to me by my website host, and I regret it. I am no longer in contact with that person, so I can no longer get the assistance I needed several times a month to get the mailbox up and running again. However, I continue to receive mail at that address.

Is there a way to automatically transfer emails from ThunderBird to Proton Mail? If so, how do I do that, please?

Thank you.

Good afternoon.

When I receive emails such as password resets, or email verifications, etc., they always contain a line such as "click the link to verify your email", and they never display correctly like they do in other email programs, and I have to literally copy and paste the link in a web browser manually.

Is there a setting somewhere that I am missing?