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I followed the instructions in the aritcle on the search page and it still didn't work. I worked with Geek Squad. They completely did all kinds of different settings and they all failed. When I click the test button, it says it connects successfully.

It tells me to retry or update the password.

I am absolutley typing in the correct password.

When I open thunderbird, the inbox say "No Messages". I then go to "File" and then "Get new messages for" account. Some times it takes several tries before all my messages (New and Old) appear in my inbox. Also, each time I open Thunderbird, I have to reset my columns.

I need assistance with a persistent Microsoft 365 authentication problem in Thunderbird on Windows 11.

My business email is hosted through GoDaddy's Microsoft 365 service. Thunderbird repeatedly fails when attempting to send messages, displaying:

"Login to server smtp.office365.com with username [business email address] failed."

We have attempted to troubleshoot this problem on several occasions without achieving a reliable solution.

Previous troubleshooting has included checking SMTP settings, STARTTLS, OAuth2 authentication and investigating Microsoft Graph integration.

Our earlier investigation also indicated that SMTP AUTH may be disabled for the Microsoft 365 account.

The mailbox works through Microsoft Outlook, but having to remember to use Outlook separately creates a risk of missing time-sensitive business correspondence.

I would particularly appreciate assistance with the following:

1. Establishing a reliable, supported connection between Thunderbird and my GoDaddy-managed Microsoft 365 mailbox. 2. Determining whether Microsoft Graph integration can resolve this without enabling legacy SMTP authentication. 3. Identifying any known compatibility issues involving GoDaddy-managed Microsoft 365 accounts. 4. Providing specific diagnostic instructions so we can establish why authentication is failing rather than repeating unsuccessful configuration changes.

I can provide screenshots, Thunderbird version information and diagnostic logs with sensitive information removed.

I would be grateful for detailed technical guidance because repeated attempts to resolve this issue have been unsuccessful.

Since upgrading to a recent version of Thunderbird ESR (a few weeks ago), I regularly receive notifications of error for a Yahoo mail account. I do not receive these notifications for other mail accounts. The notifications are as follows:

• The current operation on 'inbox' did not succeed. The mail server for account example@yahoo.com responded: p.
• The current operation on 'inbox' did not succeed. The mail server for account example@yahoo.com responded: UID FETCH completed.

I have deleted and recreated the account to no avail. Searches for similar issues has revealed nothing of use.

Any idea what is going on?

Version: 153.5.1esr (64-bit) OS: Windows 10 Language: English Proxy: None Email connection type: IMAP Authentication: OAuth2 Connection security: SSL/TLS Encryption: None

Functioning normally until it wasn't 5 days ago. Can reach outgoing servers but nothing goes beyond. Initially received emails but at this point neither receiving nor sending. No changes on my end. It just started happening.

Since yesterday , Thursday 29th October. Thunderbird has only been displaying the "Inbox" for my account, no emails are visible in it and all of the directories including the deleted emails directory and spam directory are absent. I have Windows 11 installed. I am using the IMAP server for incoming email and have checked that all the settings are correct. My account displays no incoming emails but can send emails. The directories are still absent when running Trouble shooter and the inbox is still empty. In the Account Settings - Server Settings I tested connection to the server and it said secure connection made - this worked for both outgoing and incoming servers. I have tried uninstalling and reinstalling Thunderbird but the issue persists. Although I do not change any settings the full set of directories will occasionally appear along with some emails and then seconds later disappear again. My email account is working fine on my phone and tablet using gmail.

I have several email accounts with 1&1 (Germany). Up until now, they have worked perfectly via Thunderbird. As of this morning, however, it no longer accepts any of my passwords. If I try logging in via the 1&1 webmail interface instead, everything works fine.

i sometimes send email using gmail app on mobile devices. the gmail web application shows those sent messages with the gmail sent label. Those messages dont sync up in thunderbird on my windows pc, under the gmail smtp account using the same user name. email sent from thunderbird does show up in the gmail sent folder. How to get sent email synced up between devices?

I can not down load Emails from Yahoo to Thunderbird. Every things was fine as of Aug 26th. On Aug 27th with no changes to any system settings the Yahoo Emails would not down Load. I am running Win 10 on my system. I disabled the antivirus. Reloaded Thunderbird - no effect.

I have since deleted Thunderbird and then reinstalled  latest version of Thunderbird (154.0) .
I re-entered my password. I checked the OAuth2  settings and they are set as described in the support article "OAuth2 Authentication for Yahoo, AOL and ATT". 

Message bar at bottom of Thunderbird screen shows: Myaccountname@yahoo.com:Downloading message 1 of 7 The emails do not down load - then after a few minutes - a no messages to download message flashes and then blank - nothing

I am out of Ideas. Anyone?

It is the second time. I received a message from Thunderbird asking me to introduce the passwords (several accounts), I gave the passwords and mails were coming in. This time there is no request from Thundebird.

Yandex email account. Messages are constantly being received: “Alert from account [redacted]@yandex.ru: UID fetch message 5 uid 122: failure due to backend error”. The numbers are always different. Emails are being received and sent. The server settings — the ones recommended by Yandex — are configured correctly. But these notifications appear almost every second. What is the problem?

I reset my Windows10 computer last week, reinstalled Thunderbird and got it to work as POP3 for about 5 days, but now it won't connect to my e-mail account (@prodigy.net), which I normally access through Yahoo Mail. Then on Wednesday, it just stopped working.

Last week I had to enter a passkey in as the password, but it still needed to be set as a "Normal Password". This week I have tried the same passkey as "Normal Password" which doesn't work. I tried using the passkey but specifying "OAuth2", and it doesn't work. I have tried the "Normal Password" with the password I use to get to the Yahoo Mail account on line, and it doesn't work either.

The message I get is "Authentication error" and "Unable to log in at server. Probably wrong configuaration, username or password." So, I thought I might change the passkey, but now I cannot FIND how to change, remove or create a passkey. Not at Yahoo.com nor at att.com. Can you help me? Thanks, Deb Fisher

My personal Outlook.com account can receive emails normally through Thunderbird IMAP, and sending emails through Outlook.com webmail also works.

However, SMTP sending in Thunderbird fails even though Microsoft OAuth2 sign-in completes successfully.

SMTP configuration:

• Server: smtp-mail.outlook.com

• Port: 587

• Security: STARTTLS

• Authentication: OAuth2

Thunderbird's Error Console shows:

• 535 Authentication unsuccessful

• Error during AUTH XOAUTH2

• 500 Unrecognized command 'Length: 7'

I have verified the settings and refreshed my OAuth2 credentials. The error persists.

This appears identical to Mozilla Bugzilla issue #1917321.

I contacted Microsoft Support (case #7111097598), but the agent referred me to Thunderbird without confirming whether SMTP AUTH is enabled for my mailbox.

Could someone help determine whether this is an OAuth2 configuration issue, a Thunderbird compatibility problem, or a Microsoft-side SMTP restriction?

I send an email and I get this response as a failed send. Sending of the message failed. An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: resomta-a2p-646964.sys.comcast.net ESMTP server not available (396356/173.46.82.217).

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.