Thunderbird Community Forum

Since updating to TB 153esr from the previous esr, I occasionally get a server authentication error with imap.gmail.com. Most often they happen when first starting up, but occasionally seem to happen at other times. They seem to be transient as gmail works fine otherwise.

Just wondering if this is a known bug?

After first pressing "Mark" (K), the shortcut keys for "Mark as Junk" (S) and "Star" (S) are the same. Previously, the shortcut key for "Mark as Junk" was (J). Please make the necessary corrections.

最初に「マークを付ける」（K)を押してから、「迷惑マークを付ける」（S）と「スターを付ける」（S)のショートカットキーが同じです。 以前は迷惑マークのショートカットキーは（J)でした。

修正願います。

I have Thunderbird on laptop. I make changes to a contact in the address book and they seem to be made. When I close Thunderbird and restart it, all changes are lost and are back to what the contact information was before. This has to be fixed.

Today all my yahoo & aol accounts were locked (About 10) . I had to release all 10 of them before Thunderbird can receive emails on accounts that are not locked (other than hotmail , gmail etc). I am reasonably sure this is not a yahoo / aol issue (though I know they are owned by same company Verizon Media )

Because I have seen this problem in the past with other email domains . If hotmail or gmail is locked then I cannot receive any yahoo emails until I release all locks on hotmail or gmail etc accounts

I read somewhere it may be auth issue such as OAuth2 but all my my settings are correct to OAuth2

Additional details:

• Operating system: Windows (please specify your Windows version if known)
• The issue started on August 25, 2026.
• Thunderbird becomes unresponsive shortly after startup.
• A “System Integration” prompt appears before Thunderbird becomes unresponsive.
• I cannot click any buttons once Thunderbird becomes unresponsive.
• I tested both available profiles (“default” and “default-esr”) using the Profile Manager, but the same issue occurred with both profiles.
• I also started Thunderbird in Troubleshoot Mode with all add-ons disabled, but the issue still occurred.
• I can force-close Thunderbird through Windows when it becomes unresponsive.
• I have not deleted or modified any Thunderbird profile files because I want to avoid losing existing email data.
• The profile containing my email data appears to be “default-esr”.

I would appreciate any guidance on how to identify the cause of this issue and restore Thunderbird without losing my existing emails.

When replying to an email, I type the first line of text in the text field and then paragraph (carriage return) using the ENTER key. This causes the first line of text to disappear. This has been happening all day today, several times. Closing and reopening Thunderbird does not solve the problem. Rebooting the device does not solve the problem.

Can't send emails on my computer on internet out of fredfam@frii.com since about 8/23/26. Couldn't solve problem. Added my Gmail account to Mozilla about 9/5/26 to keep being able to send some emails. Sending in Gmail failed since about 9/9/26. Problem somewhat corresponds to update of Mozilla 153.1.0. I still receive incoming emails on Mozilla laptop for both email addresses. On 9/13/26 all my Mozilla calendar events disappeared for several months and when I enter new events now, they disappear next time Mozilla loads. Running Windows 10, have not had such problems before. I've checked and changed Port settings many times, no result. My router provider detects no problems with internet connection. Is the OAuth process causing the issue with sending on outgoing server.

I have 2 Android phones. Both phones send and receive fredfam and gmail messages correctly between phones when having good tower contact. My gmail web browser account correctly shows send & receive. My FREDFAM web browser correctly shows send/receive messages.

My computer, Mozilla, receives messages sent by either phone for both email addresses.

I've had Mozilla software updates series 153.1 thru 153.2 from 8/23-9/2/26.

I had to use my Gmail password to enter this help system as my password for my FredFam account or password indentifying my laptop would not work to enter this help system. Something seems really messed up in my Mozilla setup/version. Thanks, Dave Freddy

With my new monitor, I've run into a problem with the space available for the actual message. On the attached image, I'd like to completely delete the stuff circled in red. I don't use it and it takes up a lot of space. I've resized the first two columns as much as I can, but I still can't see any of my full messages unless I open them in a new window or tab, which is inconvenient.

Thanks for any help you can give me!

Hi Support,

For the past few days I have been using Thunderbird as my mail app for office 365 account and it has been working however today I have attempted to send an email and it has stopped being able to. I get prompted to re-enter the password go through the login and the 2FA and then get to the "You're all set" response page and when I go back to the thunderbird app I get prompted to re-auth again.

Are there any troubleshooting steps I can follow to find out at what stage it is failing?

I have it configured for smtp-mail.outlook.com with port 587, StartTLS and OAuth2 selected. A username is also configured.

Thunderbird 153.1.1esr (aarch64) iMac macos Ventura 13.7.8

Hello,

When I start a new message, it's always shown 'Copy message to'. This has suddenly disappeared. (It puts copies into 'Sent'). I have 3 accounts set up; this seems to happen with all of them. I've probably clicked om something unusual, without noticing it. How can I get 'Copy message to' back again, please? Any suggestions? (I've tried clicking on things in Account Settings, without success.)

I see I've had a message from Mozilla saying 'Use 618307 to sign in'. I've been able to sign in and create thus message anyway. Is that normal, please?

Thanks for your help -- it's needed and appreciated.

All good wishes,

Roger Fern.

Roger Fern, Newcastle upon Tyne (England).

Twice in the last fortnight Thunderbird has lost all email passwords - the Tools/Settings/Privacy and security/Saved passwords just leads to a blank box where the passwords usually are. Thunderbird will no longer collect email and keeps asking for passwords for email accounts. This happens even when the option to 'save password' has been selected. I think this is probably happening at the point when the PC is rebooted. Thunderbird version 153.1.1esr (64 bit) and Windows 10. Using System Restore has not resulted in recovery of passwords. Several different email accounts/email providers are involved - outlook.com, tiscali.co.uk and zohomail.eu. Broadband provider is Zen.

I notice that the Appdata/Roaming/Thunderbird/Profiles/w2anb37y.default folder contains a number of files named with such names as 'logins.json-8.CORRUPT' - with 'Date Modified' being mostly either 17th August or today 31st August - so it might look as though password data is becoming corrupted.

Can you assist?

James

Thunderbird demands my password for outgoing SMT server when I go to send an email but when I enter it, system won't accept it even though it is the correct password. I have had this problem for some time and it comes and goes. Sometimes I have ebeen able to send without a problem, then it comes back I had a helpful reply from this forum (can't find who posted it - Mick?) tellling me to go into the error console (Ctrl + Shift + J) and delete eveything in that. I tried that. It worked at first, but now when I do it, it has no effect. And the problem now appears to have become permanent, although occasionally after I have been working for some hours, then suddenly I can send without any problem. Problem hasn't budged though for a couple of days now. This is a mysterious and erratic gremlin, which now seems to have taken root. Any suggestions please? Carol

This started almost two months ago. When I open my email on Thunderbird, the inbox fills OK. As I go through the emails at some point, several just disappear from Thunderbird? When I access my emails directly from Spectrum, they are still there, but if I refresh they may disappear.

I paid an expert on Just Answers and he spent over an hour and came back with Spectrum was having issues, they were aware and they were fixing them. I thought the problem was solved, but then it kept on happening. I am losing important documents every day! Please help me!

Since 3rd September 2026 Thunderbird opens a system integration window and then goes to not responding. I cannot access my emails through this software at all at the moment as there's no way past his pop up. Version 153.1.1, Windows 11 Home.

I moved emails from my inbox to three different folders, including my deleted folder. All have disappeared and I don't know where to look to find them. I thought it might just be the system being slow so exited and re=entered. But the emails have still not shown up in the folders I moved them to. Any suggestions as to where to look or how to recover welcome.

When I went to open Thunderbird this morning it told me the programme was already running. It certainly was. There were an infinite number of Thunderbirds running! After failing to close them all, I closed down the computer and started it again. Thunderbird was veryslow to load and when it did, the display for my inbox was of emails from four years ago. I strted to scroll down using the mouse but then I noticed it was scrolling by itself. Eventually it reached today and had downloaded some messages.

The system is though running very slowly, it takes a while for a message to open and messages which I have left open at the top of the screen for action are not showing subject or content. I operate a complicated system of filing in subfolders of messages I need to keep for reference and the subfolders seem to be ok.

I started using Thunderbird many years ago when a IT friend recommended it because, unlike Outlook, Thunderbird has an infinite capacity. I am wondering however if I have taken that too literally? I must have thousands of emails in my IN box going back years, plus a structure of some subfolders which are never used. Is that likely to be why I am having problems and would I be well advised to do a bit of a mega clear out? Advice please from the more tehnically skilled would be much appreciated! Carol

A couple of days ago we could no longer send or receive email through Thunderbird. When we try, we get the notification "Connection to server mobile.charter.net to [email address] failed" and repeatedly get the notification that our server connection has timed out. We can send/receive through Charter's webmail site, but not through our Thunderbird email client. Thank you for your help.

Lately I am seeing duplicate folders in Thunderbird when connecting to gmail. Does anyone know why/how to clean this up?

The folders shown in Thunderbird don't match what I see in Gmail. Attached are images of both views. Why are "Spam" and "Send" duplicated?

Thanks,

-Joe

It used to be than when I received a T-Bird message with a PDF attachment, I could click on the attached filename and it would open with the application I had specified in Settings (Acrobat Pro). Now I click on it and nothing happens. This is very annoying because I work a lot with emailed PDF attachements. I've tried re-setting Acrobat as the default in Settings, but that brings no joy.