Thunderbird Community Forum

I use a Thunderbird add-on named "Full Address column" on my Windows 11 system. (TBird version 152.0.1, moving soon to 156) It adds a field with the heading: Sender (@) I would like to filter incoming email based on that field. I see that I can edit a filter to customize a Message Header. Should I use Sender (@) or just Sender Or something else ? The use case is rare enough that I thought I'd ask here before experimenting.

I'm trying to setup Netzero email on Thunderbird. I get the error message, posted in question. Outgoing mail works but can't load inbox messages. I got the following error message when I first started Thunderbird - "The STAT command did not succeed. Error getting message numbers and sizes.Mail server pop.netzero.com responded: POP access disabled"

I have three separate Yahoo email accounts. I set up Thunderbird to link to each Yahoo email account separately. It worked fine for a year or more. On 5/25/26 one of the three Thunderbird email accounts stopped downloading emails from Yahoo. I could see at the bottom bar Thunderbird indicating that is was downloading 1 of XX emails, but never actually downloads them. There is no error message. I checked the Yahoo email account to verify the number of emails I am missing from Thunderbird and the number is correct. I can see the emails in Yahoo. I'm the only person using Thunderbird, so no changes have been made to previous settings for retrieval. I confirmed Security and server settings for Thunderbird in and out going emails, and Yahoo are correct. I tested the connection in Thunderbird, and the connection is successful. I tried to send an email from the Thunderbird account having issues, and the email was sent and received by the recipient. The recipient replied, and Yahoo received the email, but failed to download it to Thunderbird...along with all the other emails since 5/25/26. I unlinked the account and reestablished the link between Yahoo and Thunderbird, and still not fixed. I tried restarting the computer, with no change. I tried to send an email from Thunderbird to one of the other Thunderbird emails and it was sent and received. I made changes to Thunderbird to force the download of emails, and it still wouldn't do it. I turned off my antivirus, closed Thunderbird, and restarted it, and that didn't change anything. The capacity of emails on the email in question only has 739 emails, so it's not over the limit and I have plenty of storage capacity. Thunderbird is set to save emails, Cookies and cache were cleared, no change. I ran the folder repair feature in Thunderbird, but there was no change. I compared all the settings between the other Thunderbird emails that are working against the one that isn't, and they are all the same. There was a suggestion to close out of Thunderbird and delete the "Global-message-db.sqite" file from the Thunderbird profile in case it was corrupted, and it would recreate this file when Thunderbird was restarted. The file was recreated, but it didn't fix the problem. There was mention that a suspicious email in Yahoo might be blocked by Thunderbird, so I placed various emails in the spam folder, and it didn't work. I did find one email in the Yahoo spam folder that was dated before 5/25/26 and moved it to the Yahoo inbox. Lo and behold, that one email downloaded to Thunderbird. So there is something within Thunderbird preventing emails from downloading after 5/25/26. I've read many people complain about similar download failures with no solid fix. Someone mentioned it fixed itself on a day, but then stopped again days later. Someone else mentioned Yahoo changed its password protocol to transfer emails, but that doesn't make sense since the other two are still downloading based on the "old" password protocol. I'm at wits' end. Thanks for reading all of this. I hope someone has a solution.

When I send a message the send box does not close. It remains open and says it is saving the message in the sent folder. I then have to quit thunderbird in order to close the box and get back to using thunderbird again. It does save it in the sent folder. but the box remains open Why is it doing this?

Subject: CompuServe/AOL mail stopped working in Thunderbird 153.3.1esr — Yahoo says “invalid client id”

My CompuServe.com account stopped receiving mail in Thunderbird at approximately 1:15 p.m. Central on September 19, 2026. Thunderbird reports version 153.3.1esr, released September 18. I can still sign in and read the account’s mail through webmail.

When Thunderbird asks me to authorize access, I reach a Yahoo page titled “Review access details.” I check the box agreeing to the OpenID and OAuth terms and click Next. Yahoo then displays: “Uh-oh, looks like something went wrong. Please try again later.” Beneath that, it says: “Developers, please specify a valid client and submit again.”

The resulting URL contains `error=unauthorized_client` and `error_description=invalid+client+id`.

The incoming server’s authentication method is OAuth2. I checked that Thunderbird accepts cookies, and I have fully quit and restarted it several times. I have only one AOL/Yahoo-managed account in Thunderbird. My outgoing SMTP server is through a different provider and has worked in that configuration for years.

Could someone determine whether Thunderbird 153.3.1esr is sending a client ID that Yahoo no longer accepts, or suggest a way to restore incoming access without removing the account? I have not deleted or recreated it because I need to preserve my locally stored mail.

Just got an email from GoDaddy, my domain provider, about Microsoft discontinuing Their Exchange Web Service. My wife uses the web service but I use Thunderbird. Will Thunderbird still work for Exchange email or do I have to submit to Microsoft's extortion and use Office 365?

This is the message I got:

Microsoft will be ending Exchange Web Services (EWS) in the next few months. Your email service is not ending. We're contacting you because your account shows you may be using EWS. If you use a current, supported Microsoft application, keeping it up to date should be the only action you need to take. If you use another email, calendar or backup application, or your organization manages its own connection to Microsoft 365, please review our help article to check whether further action is required.


The deprecation of EWS is currently scheduled to begin in October 2026 and be completed by April 2027.

I have three email accounts in thunderbird, each using unique domain names. I connect through a ProtonMail Bridge to my Proton account which is also configured with the three domains I'm using. Proton recognizes all three as configured correctly and if I send from any one domains address, all domain addresses receive it.

It appears things have gotten corrupted when I was doing lots of configuring and all my email inboxes share the same contents even though Settings->Server Settings->Local Directory is pointing to separate unique directories (the original ones) for each account.

Also, the "Drafts, Sent, Archives, Junk, Trash, and Outbox" folders are gone for all three inboxes (but exist for "Local Folders". The only "folder" under each account is "Inbox", and all three accounts (e.g. larry@a.com, curly@b.com, and mo@c.com) all have the same contents where every email from every account is all in the same Inbox. They're all mixed up.

I've not a clue what went wrong other than Thunderbird doesn't handle configurations well. I've tried the Inbox->Properties->Repair Folder to no avail. In fact, when I did that, it appears to have downloaded my main accounts inbox into the other inboxes possibly resulting in the mixup of email.

Thoughts?

I can’t receive or send email’s at all

      I entered my name in the dialog box in Thunderbird Mail which is supposed to change the blocks on “Enterprise policy” to pass. The block sign is still up.   How do I that.

.

Hi!

Trying to add new account on latest Thunderbird instillation, added information/configuration what I use on another computer and in the end it says: Component returned failure code: 0x804b000a (NS_ERROR_MALFORMED_URI) [nslOService.newURI]

Checked 10x for typing errors and it says same error. These account settings works great on previous versions wihtout Account Hub

How can I solve this?

Best regards,

L’envoi du message a échoué. Une erreur est survenue lors de l’envoi de l’e-mail. Le serveur e-mail a répondu : A7kLxHMp57zNl Authentification requise, Merci de configurer SSL/TLS et votre mot de passe. Authentication Required. OFR203_402 [402]. Veuillez vérifier que votre adresse e-mail dans les paramètres du compte est correcte et essayer à nouveau.

My TB installation got corrupted due to a hardware/disk issue. On restoring it from backup TB keeps trying to download all messages again. I know this is something to do with the popstate.dat file but I can't seem to stop it. What do I need to do?

Also, I had never noticed this before (because I never looked at the TB file system) but TB created multiple folders for the email account.pop.mail.yahoo-1.com up to pop.mail.yaho-4.com. Why does it do this and is there a way to get back to just one file? Is this something to do with TB crashing or what?

Is it using all of these files or just the latest and how do I know? All of these folders have a popstat.dat file and one has multiple following the popstat-1.dat etc.

I've no idea how to recover from this. Any help would be much appreciated.

При использовании приложения Thunderbird в качестве почтового приложения возникает следующая проблема: Отправленное письмо не сохраняется в папке Sent, при этом письмо уходит получателю. Также письмо и не появляется (не сохраняется) на сервере. Я использую почту yandex, подключена по протоколу imap в соответствии с требованиями, которые они сами указывают в инструкции (Входящая почта Адрес почтового сервера — imap.yandex.ru. Защита соединения — SSL. Порт — 993. Исходящая почта Адрес почтового сервера — smtp.yandex.ru. Защита соединения — SSL. Порт — 465) Проблема наблюдается сразу у нескольких людей.

When sending an Email to multiple addresses my Mail Server returns a message that the Email will not be sent and to try again later. After deleting all of the Email messages saved up to that point the Server still refuses after many tries to send the multiple addressed Email. I have explained all of this to the Web provider and have tested the multiple addressed Email using the Severs Webmail service. They finally advised me to check with your support service to see if the problem could be resolved. I have used Thunderbird for many years and I like the software. Can you help me as the problem is driving me mad. Thankyou, Michael Brinsden

Доброго дня! Столкнулся с неприятной проблемой - не сохраняется отправленное письмо, изредка. Сегодня повторилось, и к счастью, я заметил как это произошло. Повторил те же действия, для проверки, и результат повторился. Чтобы повторить проблему пропавшего отправленного письма нужно: Нажать "создать" дважды, чтоб у нас получилось два новых открытых письма, затем прописываем адрес и отправляем одно из них не закрывая другого - готово. Теперь это отправленное письмо нигде не сохранится, но при этом адресат его получит. Разные адресаты, или какое письмо из открытых отправлять первое или второе - значения не имеет. Письма нет ни в почтовом клиенте, ни на сервере (браузерной почте моего ящика). В ответном письме будет всё как обычно т.е. полностью моё отправленное письмо со всеми файлами, текстами и т.д. Если открыть полученное письмо "в разговоре", то конечно тоже не будет исходного-отправленного письма, только входящее (ответное).

Дополнение. Пробовал с коллегой то же самое, не вышло. Так случается только у меня. Из существенных между нашими почтовыми клиентами отличий, так это то, что у меня установлены два разных почтовых ящика.

I have been a Thunderbird user for many years and have just received the following error message which I haven't seen before. Will appreciate any advice as to how to rectify the issue. "Unable to write the email to the mailbox. Make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox."

lors de l'envoi d'un email, j'ai ce message d'erreur : Une erreur est survenue lors de l’envoi de l’e-mail. Le serveur de courrier a répondu : Client host rejected by spamhaus for spamming issues; please refer to Listed by XBL, see https://check.spamhaus.org/query/ip/xx xx xx xx for further information.

On September 16, 2026, just before midnight, my Thunderbird received its last email. We have been using POP3 hosted by iPage (recently merged with Network Solutions.) If I log into Roundcube webmail, we are still receiving all our emails. Thunderbird can still SEND emails, but cannot RECEIVE ANY email. Literally nothing happens when i toggle the "download" icon; no messages, no prompts, Nothing happens. Please help, I need to get our Thunderbird working Again. Thank you, Duane Delp, Operations Nextru,Inc. www.nextruk.com