Thunderbird Community Forum

Thunderbird says "certificate for mail.capsense.com is not valid for that server..." and hangs. Then awakes in 10 minutes.

I've been getting this message for months without problems.

It's very odd. Normally moving an email, say from the Inbox to the relevant year's archive, takes "no time at all".

Which is true for all the mailboxes shown on the attached screenshot, EXCEPT for the four at the bottom. Moving even one message from Inbox to Yiddish can take ten seconds or longer (with the dreaded "Not Responding" occasionally). Moving something in the opposite direction is also screwy, only from those four.

I had thought that it was because they're rather large. This first started when there were just Yiddish and MSW, and I split off most of the earlier years into the archives shown. To no avail.

It's only an annoyance, but I'm puzzled about how such a thing could happen.

Also very slow tagging or untagging a message just in those mailboxes.

Moderator Notes:

• need a performance profile https://support.mozilla.org/en-US/kb/profiling-thunderbird-performance

I'm on a 15" MacBook Air M5 running and updated OS to Golden Gate 27.0 a couple of days ago. when I Open Thunderbird the emails are up but page is blank, just spinning pizza wheel. I've force quit Thunderbird and restarted and force quit and shut down several times but ends up with the same result... just the spinning wheel. Any suggestions ?

Hi, hoping someone could help as I am struggling to get my information back. I am using Ubuntu Cinnamon.

Thunderbird crashed last night, wouldn't work, tried safe mode. Nothing fixed it. It hung when opening up and after 30 seconds said force quit. So I was forced to reinstall. I did a manual backup but not using the inbuilt tool as I couldn't get into Thunderbird. I just copied the data from username/.thunderbird

After spending a long time uninstalling. Because it reached 78% and then crashed on uninstall. Eventually after reading various pages on the internet I managed to reinstall from the Ubuntu software manager using the latest snap version. (Which I am not sure was what was actually installed previously).

However having used thunderbird for nearly 20 years or so. I have a username/.thunderbird folder. And when I moved to this platform, I have a snap/thunderbird/common/.thunderbird folder.

I installed this new distro 2 years ago, and remember having issues getting my data into the system under Snap. But eventually got it to work somehow back then.

However since reinstalling I cannot see the last 2 years of emails, archives or data. It has launched into a 2 year old profile. I appear to have lost most of the emails from the archive folders (but kept the folders) removed all of the personal folders but then dumped all those emails into my inbox. Giving me 6500 emails that were in various personal folders. (I don't get 6500 emails in a year so don't know what has happened.) It has even changed all of the new dates to the US format, so nothing makes any sense.

I now have 2 Thunderbird profiles, over 12GB in size. And have apparently lost 2 years of my life. But reading support pages, suggests I should be okay because thunderbird doesn't delete data when you reinstall?

I have looked through various other threads which talk about pointing it at the profiles and mail boxes, however nothing works.

Any help much needed.

I am using TB as my email client. I use it to manage my email from Greenby who are an email and web hosting service operated by Enix Ltd. The ISP Plusnet has migrated customer's email from their servers to Greenby's as they no longer provide an email service. I am in the process of leaving Greenby (A look at TrustPilot reviews will tell you why.) At some point I will be closing my Greenby account as it attracts large amounts of spam and scam emails, which it is time consuming, difficult or impossible to block.

I want to archive my email to my hard drive and I have read the guidance on how to do this using TB. I am quite happy to keep the TB software on my PC.

Will I need to keep TB software to read my archived email? Does TB function if it not acting as a client from a third party server?

Any thoughts or advice would be appreciated.

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."

Bonjour, hier j'ai installé Thunderbird sur mon nouveau MacBook, j'ai récupéré tous mes mail, mais en fin de journée, il a disparu. Comment fais-je pour le réinstaller sans avoir à verser un nouveau don ? Par avance merci pour votre aide. Pourriez-vous me joindre au X Cordialement, Catherine

(PII redacted by moderator)

Until a couple of days ago, I could single-click on a message and the contents would show up in a column in the same window. Now (presumably because of an upgrade to 156.0.1) this does not work. I have to double-click and then the message appears in a new window or tab ... which I then have to close. Very irritating! The earlier way meant that I could quickly scan through messages with far fewer clicks. Is this how it is now or is there a setting I could use to revert? On my other computer, I still have release 154.0 and I see the earlier (good!) behaviour! Help!

People I frequently get email, whose email addresses are in my address book keep getting placed in spam. I thought this wasn't supposed to happen. I have to go through my spam folder every day looking for legitimate emails from people I know.

hi, i'm trying to view my saved passwords as i used to be able to but now it asks for a sign in! user name and password! i don't know what this refers to as i never had to sign in to view passwords. i need to get them for a new computer i just bought! i need those passwords. please help! thanks for your consideration. peace, James Glynn

At least two of my contacts contain more than one email address, but not all of the email addresses appear in TB; the relevant cards in TB contain some but not all of the addresses in the macOS address book.

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.

September 24, 2026 Hello. The Mozilla Firefox express connect to email icon on the taskbar shows a superscript of 2. I have no unread emails in either of my mail accounts. What is the 2 indicating? It has been like that for a couple of days now. Please help. Thank you. Helen

My Gandi accounts will not connect. I know they are correct; I know my passwords are correct. They are my main emails; if I cannot use them, I cannot use Thunderbird?

I had to reinstall Thunderbird after doing a clean install of Windows 11.

Since installing, the expected login popup for Gmail doesn't appear. I get the attached error message instead.

Yahoo worked fine after a few tries. What is the problem here, and how can I fix it?

Used old method to setup email accounts and it worked fine. New UI will jam the user name and host name and host name together for new email account setup. In UI for: Username It will have the full user and host together eg. test1@test.com Then during account setup after you enter password, I can see it on the bottom of the UI panel, so like this... test1@test.com@test.com When you go back it will put in the Username field, test1@test.com even when you deleted the host test.com from it. Also the host field screws up. It will put a period in front of the host name eg. .test.com So you have to delete the period.