Thunderbird Community Forum

‘I can login to Orange website & read my mails: Thunderbird, using same password, gets "Authentication Failed", This on 2 accounts.’ for ‘Thunderbird’. This is a recent problem, occuring after a series of"Account blocked , due to suspicious activity"

Out of the blue Google started blocking one of my Gmail accounts on Linux Mint. It's been running fine for months. The rest run fine. It kept giving me this error message.

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.

I installed that account on my windows box with exactly the same information. I cut and pasted it in fact. It went right through with no problems.

It's one of my main accounts and it's dead in the water. I deleted it and tried to reinstall it and I have exactly the same problem. Setup information. Hit continue. "Configuration found" Click done. Goes to "Sign in to continue to Mozilla Thunder bird Email" Put in email address. Click next and I get that error message. Help?

Captain Quack.

I changed my password in my Juno account and have logged in via a browser with the new password several time. But Thunderbird attempts to connect continue to fail. I deleted the old password in Thunderbird in the Privacy & Security section thinking it would update when the new password works - unfortunately, it never works. I reviewed all the Juno settings in Thunderbird and they are all consistent with the Juno Support recommendations. Now what?

I am trying to add an email address to Thunderbird on my laptop and I keep getting an authentication error when I enter the password. All the same information has been used for the same email address on my phone and works fine.

T-Bird's pop-up window requesting password keeps popping-up on my screen every 15 to 30 minutes or so ALL DAY, regardless of whether or not I fill-in the password or cancel the po-up. No idea how to make the sun-on-da-beach stop! PLEASE, anyone that has experience w/this... HELP!!!

Hello,

I'm having an authentication issue with Thunderbird on Fedora when trying to add a second Microsoft account.

My main @outlook.com account works without any problems using IMAP/SMTP and OAuth2. However, I can't get my @outlook.fr account to work.

For the @outlook.fr account, I'm using:

IMAP: outlook.office365.com, port 993, SSL/TLS, OAuth2 SMTP: smtp.office365.com, port 587, STARTTLS, OAuth2

When I add the account, the Microsoft login page opens normally. I sign in with the @outlook.fr account, complete 2FA, and Microsoft confirms that the account has been successfully connected to Thunderbird.

However, as soon as I return to Thunderbird, I get an authentication error saying that it was unable to log in to outlook.office365.com with that username.

I've already tried clearing Thunderbird's saved passwords, cookies, and web cache. I also confirmed that IMAP is enabled in Outlook web settings, checked the account aliases/sign-in preferences, and verified the server names and ports.

Since the Microsoft authentication itself completes successfully, I'm not sure why Thunderbird fails immediately afterwards. The same setup works with my @outlook.com account, so the problem seems to be specific to the second account.

Has anyone encountered this before, or is there anything else I should check?

Thanks.

Dear Thunderbird Support Team,

I am unable to log in to my email account through the Mozilla Thunderbird desktop application. I am getting an “Authentication Error” stating that Thunderbird is unable to log in to the mail server and that the username, password, or configuration may be incorrect.

However, I have verified that the same email credentials are working correctly through webmail, so the account password is valid and the mailbox is accessible.

Issue Details:

Application: Mozilla Thunderbird Desktop Issue: Unable to authenticate/login to the email account Error: “Authentication error – Unable to log in at server. Probably wrong configuration, username or password.” Webmail Login: Working successfully Thunderbird Login: Failing with authentication error Operating System: Windows

I have already checked the email credentials and attempted to configure the account in Thunderbird, but the issue persists.

Kindly help me identify the cause of the authentication failure and provide the correct Thunderbird configuration/settings required to access the email account.

I can provide screenshots and the current Thunderbird account configuration if required.

Thank you for your support.

This notice fairly regularly appears in the last couple of weeks - I do not trust the AI solution as everything APPEARS to work normally on Thunderbird - were it not for that notice I'd think all was normal! Is rectification of something needed? If so simple instructions needed and advice as to the cause - I'm no techie and wonder if I meddle I'll cause problems I currently don't seem to be experiencing.