Forum zgromaźeństwa Thunderbird

bob.fannon

Feb 14, 2026, 13:01 CST

I have used Thunderbird for a number of years with Plusnet (using POP settings) in the UK. However, Plusnet has transferred their support to a company called Greenby who have made a hash of it and offer very poor support. So, I want to use Outlook as the mail server but I am unable to send any messages via Thunderbird to the Outlook server. I can however download messages with no problems. The error message I get is :- Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) smtp.office365.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'

My default Outgoing Sever settings are :- Server Name : smtp.office365.com Port: 587 User Name: bob.fannon@outlook.com Authentication method: OAuth2 Connection Security: STARTTLS

I have tried deleting the Thunderbird account and re-creating it but still got the same result. I also tried to use my old Icloud account ( having first setup my App Specific password) but got the same result.

When a message is removed from a folder via that folders' Retention Policy, is the message permanently deleted or does that message go to Trash? I use Thunderbird with Gmail via POP. Thank you.

おとといからYahooメールの受信が出来なくなりました。 その前にはいつも通りできておりました。

Thunderbird上で起動時の送受信時にPOPサーバーへのログインに失敗しましたと表示されます。 パスワードを変更した覚えもなく、いつものパスワードを入れましたが、ログインできず送受信が出来ません。

こんな感じですが、よろしくお願いいたします。

My old calendar kept events in Reminder mode until I dismissed them. Thunderbird dismisses them too soon. Can I force it to keep displaing the reminders?

I did something one time, but it suddenly showed a whole month of reminders! That was too much. I just want to be the one who decides to dismiss. Thanks.

When I send a message, it actually is sent, however the windows showing send progress continues on for some time, after which I need to click on cancel to close this window. At first I did not think the mail was being sent, however after replies on them were being received, and when sending an email from one of my email addresses to another, I get the windows message that the email was received. Why isn't the process window closing when the message was actually sent??

I was sending an email with an attachment I wanted to check the attachment before I sent it. But I chose windows media player and it won't work I went to remove media player but I couldn't open my attachments, so I put the attachments back on but I still can't open my attachment. What do I do so I can Read my attachments again Thank you Richard

Changed my BT mail password. I can receive mail but when trying to send I am asked to enter password which is not recognised. The SMTP server does not reccognise this. I have checked other questions and all seems well in my settings, i.e. changed stored passwords, but I must have missed something.Any advice most welcome Don

Hi,

Since updating to Thunderbird 140.7.1esr (64-bit) on Windows 11, moving messages from Inbox to any folder takes about 7 seconds.

Details:

Account type: IMAP (Cogeco)

Happens in all folders

Inbox has ~600 messages (not large)

Was working normally before the recent update

Delay occurs every time moving a message from Inbox to another folder

No freezing — just a delay before the move completes

No antivirus changes

Issue started immediately after update

This appears to be related to IMAP sync behavior introduced in 140.x.

Has anyone else reported this, or is there a known regression?

Thank you.

Hallo, ich habe meine E-Mail-Konten in Thunderbird umgestellt von POP zu IMAP. Meine Filter-Einstellungen waren bisher gültig für "Lokale Ordner" (die Filter musste ich manuell starten) Wie kann ich die Filter-Einstellungen auf den Posteingang meiner IMAP-Konten kopieren/migrieren? Danke, und Grüße aus Berlin

I have added a new outlook email account to thunderbird. I have checked and have the most recent update 147.0.1.(64 bit). It added the email, I can test connection to server and passes. When I try to get or send email I get either authenticated but not conected OR Command 12 error. I have IMap setting turned on in outlook and added thunderbird as an app.

I am trying to create my outlook.com account in Thunderbird. I see the Account Hub box, and have typed in my email address. But when I type in the password, I get an error message, "Authentication failed. Please check the username and password". It then says, "Exchange auth error". I have checked and double- and triple-checked the spelling in the email address and password, and signed in to my email via the Microsoft outlook.com page using the same email and password. I can sign in to my email using the latter method, but Thunderbird keeps giving me the same error message and won't create the account in Thunderbird. What am I doing wrong?

Hi, I have followed the instructions for incoming and outgoing servers to convert my Juno Webmail to AN MBOX FORMAT and bring it over to Thunderbird. However, it is not syncing up to Thunderbird and bringing in all of my old emails from Juno.

Any help you can offer with this situation would be greatly appreciated.

Thank you

Carla

My emails that are in Sent or All Mail are all out out order by date - random - different dates. I don't know what happened? I expect to see the most recent first - just as i do in my inbox. It is ok. They are fine in Gmail - where they come from. Thanks

I have used Thunderbird for a long time?

My email set-up is a mess. In December, when I had a problem, my provider told me to open a new account, which I did. Both my old and new accounts received emails for a few days, and then only the new account was receiving emails. Now I find that my drafts and sent messages are saved to the old account, and suddenly yesterday I was unable to send emails, from either account.

I keep getting this error message: "Sending of the message failed. Peer reports incompatible or unsupported protocol version.: The configuration related to mail.activ8.net.au must be corrected"

I have no idea what this means or how to correct it.

My husband and I use the same internet provider activ8 and access it through Thunderbird. I have a new computer. Received a configuration code from Activ8 and I can receive emails but not send them. Get the message PEER USING UNSUPPORTED VERSION OF SECURITY PROTOCOL. THE CONFIGURATION TO MAIL.ACTIV8.NET.AU MUST BE CORRECTED. How do I do that? Activ8 says they can't help.

I am running Thunderbird 147.0.1 (64-bit) on Windows 11 Pro 25H2. I have Thunderbird set up with two email accounts -- gmail and outlook.com (an old msn.com address). Approximately every 10-14 days the msn.com account encounters an error with the message "Command Error 12." When this happens, Thunderbird immediately drops all the local email folders for the msn.com account, and attempts to redownload all email and folders associated with the account. The msn.com account in question is configured for IMAP:

server name: outlook.office365.com Port:993 Connection Security: SSL/TLS Authentication Method: OAuth2

The expected behavior here would be for Thunderbird to display a connectivity error message but retain all local email on my laptop. However, this specific connectivity issue is dropping all locally stored email. I also noticed that the mail columns get reset to default. It appears this issue is causing Thunderbird to delete not just the email but some of the account configs as well.

At present, I do not have a screenshot showing the command error 12 message. I will try to take a screenshot the next time the issue occurs. What is not clear is whether this is an account setup issue or a bug in Thunderbird. Any advice would be appreciated. Thanks.

I inadvertently deleted a mail sub folder named Shopping Oder Confirmations I found the folder in my acronis backup and copied it to my desktop I then pasted it in to the profile window of thunderbird in hopes that when i restarted it would show up in my mail folders which it did not I can send you screen shots of the different windows where I dropped the folder Can you help please?! There is tons of information in these folders I reference often. Thank you! BTW I did just make a donation :)

In initial set up of Thunderbird laptop: on the last screen of set up, after entering username and password, Thunderbird set up posts a green background notice: " [checkmark] Configuration found in Mozilla ISP database." When "Done" is selected, a the following yellow background notice is posted: "Unable to log in at server. Probably wrong configuration, username or password." I know username and password are correct; they allow access to email via Spectrum webmail. I am confident configuration is correct [IMAP] \,because that is the configuration I have always used with my Thunderbird account on other computers. Suggestions?