Yonke imikhiqizo Community Forum

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.

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?

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.

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?

I can receive mail fine. Cannot send mail on gmx.co.uk acct, but gmx.net works on oauth2. But oauth2 is missing on gmx.co.uk It's just not on the pulldown. I tried a new thunderbird acct for gmx.co.uk but oauth2 is still missing.

Can not send emails to a newly created outlook.com (free) account. Have tried dozens of different settings, approaches.

My current setup:

 - windows 10
 - thunderbird 140.8.0esr (64-bit),  numerous previous versions also do not work
 - outlook.com (free) account mail provider
 - POP3 enabled (tried IMAP enabling also) on outlook.com account
 - no 2FA or 2FA enabled on outlook.com account, no difference
 - outlook.com web access works fine
 - followed instructions in mozilla support article Microsoft OAuth Authentication and Thunderbird in 2024 
      (https://support.mozilla.org/en-US/kb/microsoft-oauth-authentication-and-thunderbird-202)
 - have done a fresh install on a new machine without an existing profile.
 - have tried various microsoft servers, have tried oauth2, normal password
 - thunderbird account creation works just fine.
 - server settings and SMTP settings match as recommended by support article noted above
    SMTP server settings
        server name: smtp-mail.outlook.com  
        port: 587
        connection: STARTTLS
        authentication: OAUTH2
        user:  xxxxxxxx@outlook.com

symptoms:

 - receiving(downloading) emails works fine.
 - sending emails fails with following messages
     Login to server smtp-mail.outlook.com with username  xxxxxx@outlook.com    failed    followed by 
           Unable to authenticate to Outgoing server (SMTP) . Please check the password and verify the 
             'Authentication method' in 'Account Settings | Outgoing server (SMTP)'

Many people seem to be having this issue with no resolution.

Please help.

Created new yahoo mail IMAP (PKCE) account using Thunderbird account creation. All seemed to work well. However, new account does not receive mail from "some" other IMAP and POP accounts in testing, including from TB Pro. Strangely, mail sent from oldest POP accounts works. Mail from newer POP gmail and TBPro accounts is not received. TB 149.0b1 Windows 11

Connection to pop.mail.yahoo.com times out and no emails are downloaded. A new windows appears from https://login.yahoo.com/ that I have never seen before asking for username and password but this returns a "something went wrong" error. Is there an update, or a setting change, that resolves this problem?

Thanks

Frank

Some months ago I received an email, but the body of the email was a picture (jpg) from my computer. The sender definitely does not have the image. The content from the sender is missing, and my image is in the body of the email and as an attachment.

This has happened a handful of times over the past 6-9 months, with the same image showing up in emails from various unrelated senders.

I just received an email from my partner who sent me an email with a screenshot attached, but instead of receiving what he sent, I've got an email with my image that randomly shows up in my inbox.

A few days ago it happened, but when I restarted my computer, the unwanted image was no longer present, and the actual email content was visible.

Restarting my computer has not resolved this particular instance.

Does anyone know why Thunderbird is in love with this one image of mine and why it keeps showing up in my inbox in emails from other people?

Возникает ошибка:

Ошибка отправления сообщения. Сообщение не может быть отправлено, так как не удалось установить соединение с Сервером исходящей почты (SMTP) «smtp.gmail.com». Сервер может быть недоступен или отказывать в соединении по SMTP. Убедитесь, что указали корректные параметры Сервера исходящей почты (SMTP) и попробуйте снова.

Edition Windows 10 IoT Enterprise LTSC Version 21H2 Installiert am ‎18.‎09.‎2025 Betriebssystembuild 19044.6937

Thunderbird Version 148.0 von Feb 2026

bis zum 5.3.2026 funktoinierte TB einwandfrei, aber seit gestern kann ich keine Mails mehr versenden, folgende Fehlermeldung wird angezeigt siehe Bild Hochgeladen. Gestern wurde die IP 18.195.155.157 angezeigt, heute 3.70.126.251

Empfangen von E-Mails hat funktioniert nur beim Senden oder Weiterleiten kommt die Fehlermeldung.

es Spielt auch keine Rolle von welchem Konto ich Mails verfasse, ob T-online,Web oder Agenturserver

Benutze den Acount auch auf einem Laptop mit W11, dort funktioniert alles,

Die SMTP Einstellungen hab ich überprüft, Laptop und diesem PC sind identisch (Hatte ja auch keine Änderung in diesem Bereich durchgeführt)

Hi everyone! Why do I get an error when I try to download messages - "Failed to save message. Check the spelling of the file name, wait a while, and try again"

And the most annoying thing is that after this error, downloading other letters stops and you have to manually search for that very letter, although there may be thousands of them... Please fix this!

I have both a Microsoft 365 email account and a outlook.com email accounts. I'm using version 148.0. Both account set up just fine. When I delete an email from either account after a couple of seconds I get a message saying "The current operation on 'Inbox' did not succeed. The mail server for "the account name" responded; [TRYCREATE] The destination mailbox could..." that all I can read. Why?? It is only on the Outlook accounts. I have several other account set up and they all delete the emails.

Dears since yesterday i cannot download yahoo mails to thunderbird on my windows computer. when thunderbird gets new messages, a window pops up asking me for yahoo account name and password. when entered yahoo gives the following message: " Something went wrong. We could not sign you in. Try again from a different device." i use thunderbird 148.0 on windows 11 (out of china, with Astrill VPN - all other websites work normally with VPN). i have three different yahoo accounts, the first time thunderbird asked yahoo first mail and authentification went through, but it does not go through for the remaining two accounts. i verified that OAuth2 is set up for all accounts. password is correct (as i can still receive emails on iphone mail app). cookies can be accepted without any exceptions, can see the whole OAuth2 dialog panel. i did all steps for setting multiple accounts. i verified all accounts for POP and STMP server settings. also mailnews.oauth.usePrivateBrowser set to TRUE. After all this, it still does not work (i also restarted thunderbird and the computer), what else can i do? Regards Violaine

I received an email on 02/25/2026 that was a egift card from a local small business. The egift card was from with Square account. When I went back into my inbox the next day to use the egift card, the email was gone. I looked in all my folders and didn't see it anywhere. How can an email just disappear? When I contacted the small business, they said they can't honor the egift card without the 16 digit # on the egift card. I showed them the receipt for the purchase but it doesn't not show the 16 digit code for the ecard, only shows the purchase of a gift card. So how do I find this email with the egift card?

this was the email address from the purchase invoice. noreply@messaging.squareup.com

I don't recall the actual email address the egift card was from other than I saw it was from a Square account.

Thunderbird 147.0 (64-bit) OS: Linux; Fedora 43 Settings:

• smtp.gmail.com
• port 465
• SSL/TLS
• OAuth2
• full email address

This situation started happening about a week ago. I created a new user and had no problem sending email from the same default account. I can also connect to smtp.gmail.com using telnet, port 465. Something is presumably corrupted. I have had this account for many, many years, so I have accumulated many filters and other data.

I have an outlook work email account in Thunderbird. Now I need to add another for a charity role. The first/work one is fine, but I can only receive emails on the second/charity account. I've tried different setting for the outgoing server but I don't really know what I'm doing with that - can you help please? Thank you.

Sending an email slowed right down, so I saved it and tried to open it from the Drafts folder, a local folder. Drafts was agonizingly slow to open a draft. (I tried this several times to send a particular email.) I clicked the Repair Folder button for Drafts. Then I clicked the Repair Folder for my local Sent folder. Bad move. Suddenly Thunderbird started resending all the emails in my Sent folder. Starting in 2020.

I had to disable my internet connection, then change my Sent Folder back to a server folder and disable my SMTP settings for the moment. Ouch!

Thunderbird doesn't seem to work well with local folders any more.

Hello Thunderbird Community Help!

After reviewing and implementing all the suggestions on the Mozilla/Thunderbird support pages and on the internet, I still cannot send emails from my office365 mail account from Thunderbird. I was able to send/receive email messages until about 4-5 days ago. From several different accounts on my laptop. And from two different laptops: one using Windows 10 and the other 11. Now, both will receive emails to their inboxes but neither will send a message.

I have the various set-up parameters set as recommended for SMTP using Oauth2, see below and the attached photo:

Outgoing (SMTP): Server: smtp.office365.com Port: 587 Security: STARTTLS Authentication: OAuth2 Username: Your full Office 365 email address

I have deleted the stored password hundreds of times. I have deactivated MFA with Microsoft. I have deleted the e-mail profile in question many times, and have re-created it using automated and/or manual configurations. And I have deleted stored passwords.

I keep getting this message:

"Login to server smtp.office365.com with username [my.email.address] failed." With three button choices: "Retry" "Enter New Password" "Cancel"

No luck with Retry or Enter New Password. They both result in a brief, failed re-attempt to send the email message, and a return to the previous message and choices.

Pressing "Cancel" results in this message: "Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) . Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'."

Additionally I've reset my MS password several times. And MS seemingly is uninterested in having TBird/me login to my office365 account. I just get this response repeated over and over:

"Login to server smtp.office365.com with username [my.email.address] failed." With three button choices: "Retry" "Enter New Password" "Cancel".

I've spent a LOT of time over the past few days and over the weekend looking for a solution, but nothing so far has worked and I'm at my wit's end!!

Any help that you folks far more experienced with TBird can give me to get things working again would be GREATLY appreciated.

Best regards...

Tony