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I then click on cancel to get it off my email screen. However it continues to pop up whenever I try to get my email, even though the mail comes through, it says can not connect to server. Very confusing. Anyone have this issue?

I've been using Thunderbird on a Windows machine for years. I now have an iMac and recently downloaded Thunderbird to start transitioning over. When I try to set up an existing Email address, the configuration is found in the Mozilla ISP database. After I enter the password though (mobile.charter.net), I get an error stating "Unable to log in at server. Probably wrong configuration, username or password". The password is correct and works on the Thunderbird version on the Windows machine. I have multiple Email addresses and I get the same error on all with verified correct passwords. Any help to correctly install would be greatly appreciated!

I have been using Thunderbird for a few months and changed my Google Password(even though Im not quite sure if the error wasnt already occuring before that), but now when I go on Thunderbird it gives me a popup window that says "Enter credentials for name@gmail.com on imap.gmail.com". Theres a field for the email-adress, but when I click "Next" theres the following error: "400. That’s an error. The server cannot process the request because it is malformed. It should not be retried. That’s all we know."

These are the things I tried: Entering the old or new Password. Checked if the config is set to OAuth2 in both incoming and outgoing servers and enabled on Gmail-Account. Deleted and tried to (unsuccessfully) reregister my Thunderbird-Account. The same error pops up when it checks my password after the configuration.

I dont know if the password change is actually the cause, since I think I remember the error message appearing earlier today, before I changed the password, but Im not sure. Also, I have another account linked to my Thunderbird, with no changed credentials, and while there is no similar error message, thunderbird suddenly also has problems connecting to it and asks to retry a few times (3-4) before actually connecting everytime I open it.

Good afternoon!

Thanks for the great customer!

We have several computers on a local network without internet access. There is a problem in Thunderbird 143 - files are downloading slowly. POP3 and IMAP are the same. From several tens of seconds to one and a half minutes, 11 files from the letter were downloaded, totaling 20 MB. There is such a feature - if you disconnect the network adapter, the problem practically disappears. There was no such problem in the Thunderbird 115 version. The Em client and Mailbird clients were also installed for the experiment - they also do not have such a problem.

The mailbox is small and contains 20-30 almost empty emails.

Tell me, please, what can be done about it?

Sincerely, Yaroslav.

Hello. For years I've been successfully using your browser. Now it keeps giving messages that say "Try Again" .

We can’t connect to the server at links... bla blah

Server Not Found

...PLEASE ADVISE

When I open the Thunderbird desktop app we receive this popup error message:

"Unable to establish TLS connection to POP3 server. The server may be down or may be incorrectly configured. Please verify the correct configuration in the Server Settings for your mail server in the Account Settings window and try again."

I have not found any configuration under the account settings to help with this, but if anyone has any suggestions to walk me through this to establish a connection again that would be most appreciated.

Additionally, when I try to send an email I receive the message: "Login to server smtp.cybermesa.com with username centinela failed."

After closing the error message box I received another error message: "Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.cybermesa.com timed out. Try again."

Is our issue then with Cybermesa and not Thunderbird? Or Is something wrong with Thunderbird due to our initial error message we received? Any suggestions is much appreciated.

I keep getting this message from google: "400. That’s an error. The server cannot process the request because it is malformed. It should not be retried. That’s all we know.” (see screen grab attached)

本件はIMAPでMicrosoft365アカウントをサインインしようとしたときに発生している事象です。 最初のユーザー追加画面で氏名とメールアドレスを入力します。 その後、メールアカウントの種類を選択する画面でIMAPを選択して「続ける」をクリックしても「設定を検証できませんでした。ユーザー名とパスワードが正しい場合は、サーバー管理者があなたの選択した設定を無効化している可能性があります。別のプロトコルを選択してみてください。」と表示され追加ができません。 上記メールアカウント選択画面で「設定を編集」をクリックしても結果は同様ですが、「詳細設定」→「テスト」をクリックすると、「次のアカウント設定が、指定されたサーバーを調べることにより見つかりました: 」と表示はされます。 しかし、続けようとすると「受信サーバーの設定がすでに存在しています。」と表示されてしまいます。 なお、Exchangeを選択した場合は追加できます。 Microsoft365アカウントについてはIMAPを有効化していますのでアクセスがブロックされているわけではないと考えています。 解決策を教えてください。

I just installed NORD VPN, and I can no longer send any emails in Thunderbird. Receiving is just fine. Gmail works fine. The addresses in Thunderbird are all Spectrum charter.net addresses. I have spent over 5 hours trying to get his working, seeking help from every possible source that I could think of. The spectrum addresses can send and receive just fine when logging into spectrum. This is probably a pretty common association, that is Nord VPN and Thunderbird. And with the big black Friday sales there should be plenty more people with the same situation. If you can give me any ideas about a solution, I would be most grateful. Thank you Bill Lowe

Won't connect to Host Server. The error notification window won't allow me to get back to the app to check settings. The only option given is "Try Again". I don't know why it all of a sudden won't connect, because my iPhone connects just fine

Thunderbird cannot setup Outlook mailbox after upgrade to Windows 11

clearing passwords from the credentials caches in TB and windows makes no difference. Changing the password for the Outlook mail account and verifying it makes no difference.

No problem with 14 Gmail account accounts

Outlook and Thunderbird are a buggy pair. They will waste hours of your time. Experts will tell you that you’re an idiot and it’s really simple. But they can’t describe how to simply start from scratch and add an Outlook account. They just assume it works naturally for everybody because it worked for them. Maybe it does work 60% of the time. Good luck plan to spend a frustrating evening and then think about something other than Microsoft and Mozilla.

I have 3 different email accounts on Thunderbird. All was working perfectly yesterday. Today, none of the email accounts can connect with their respective email servers. (Two are Verizon/AOL and one is gmail.) I have tried various fixes with no joy. At this point I give up. My email is very important in my life (I'm 81 years old) and Thunderbird is simply way too hard to fix with non-existent help. (Your Community help line is a joke unless you have technical knowledge. Nothing ever quite fits the problem so it is no help at all.)

I received this message: Unable to connect

The connection was refused when attempting to contact localhost.

   The site could be temporarily unavailable or too busy. Try again in a few moments.
   If you are unable to load any pages, check your computer’s network connection.
   If your computer or network is protected by a firewall or proxy, make sure that Thunderbird is permitted to access the web.

I am not receiving new email. What do I need to do to get it working again?