Thunderbird Community Forum

Around Jan. 4, I tried moving all of my Inbox contents to a new subfolder "Inbox 2025". This process was taking a long time and I didn't see it complete. Afterwards, I can start Thunderbird OK (version 115.3.1 (64-bit) running on a Windows 10 system). I see the new folder "Inbox 2025" and it seems complete. I also see other folders which look OK. But the incoming messages have frozen at 01/01/26 [for one e-mail account] and at 01/04/26 [for a second e-mail account.]

It is also true that all of my Thunderbird sessions end by crashing after a certain period of time. What can I do to restart Thunderbird so that it will connect with the relevant servers, get new messages and not crash?

If I begin typing while before I begin a new message, sometimes a message will disappear and I can never find it again. For example an "A" will move it to the archives. But whatever letter I press, the message disappears. It's not in archives and not in trash. How do I find it again?

Hello everybody. Since today or yesterday, my Thunderbird has stopped refreshing the list of messages. The number of new/unread messages in the Inbox and other folders is shown and updated right but the main window with the list of the messages does not get refreshed and only shows the last message from couple days ago.

I've tried to follow a bunch of guides and ideas (repairing folder, deleting .msf files...) and even removed the account and tried adding it again. The list of folders is right but now there are no messages at all. All folders look empty.

I've found out that in the folder on the disc where there are supposed to be the "INBOX.msf" and "INBOX" files, that the "INBOX" file without the file type is missing. And it's the same with every message folder, there are only .msf files on my PC where I removed and re-added the account. On my laptop, the "INBOX" file still exists but does not get updated.

This thing is happening with only one of my e-mail accounts, the others get updated fine and new messages are shown. It is IMAP server, imap.atlas.cz, Port 993, SSL/TLS with a password.

Can anyone help please?

Hello:

I am unable to send email messages to any "@zianet.com" email accounts (New Mexico). I can receive Zianet email messages, but I cannot Send or Reply. Zianet says they recognize the Earthlink IP Address, but that there is a third sender's IP Address they don't recognize. Earthlink says they have given Zianet the IP addresses. Does Mozilla Thunderbird have a third IP Address I can share with Zianet Tech Support? Zianet's phone number here in Las Cruces, New Mexico is: 1.575.353.1234. This issue is causing a lot of problems for me and my business. Thank you so much.

Here is the error message:

Delivery has failed to these recipients or distribution lists:

Server "zianet.com" returned an error:

* [hpollard@zianet.com]: message reached max retries

Authentication-Results: earthlink-vadesecure.net; auth=pass smtp.auth=jeanfulton@earthlink.net smtp.mailfrom=jeanfulton@earthlink.net; Received: from [192.168.10.102] ([67.143.180.56]) by vsel1nmtao01p.internal.vadesecure.com with ngmta id 48c82eca-188a1cab439a7dda; Mon, 12 Jan 2026 22:35:32 +0000 Message-ID: <35210bba-27ea-40e6-858d-5d16b6b6d300@earthlink.net>

I have a set of e-mails that I am unable to delete or move - when i try they disappear for a few seconds and then re-appear. They all contain a red bold warning "Caution external e-mail"

Bonjour, Depuis le 13 janvier 2026, tous les mails que je reçois vont directement dans le fichier "Quarantaine". Je ne reçois plus aucun mail dans la boite de réception ?! Je suis désemparé car je n'ai pas le souvenir d'avoir réalisé une action particulière de paramétrage. Cordialement Gérard Caparros somedex@sfr.fr

In earlier versions, the calendar list button appeared in the left sidebar, so I could decide which calendars to display and change the default color. But I can't find this now. How can I change an existing calendar?

Hi Thunderbird, At the weekend we accidentally completely deleted some Gmail emails from Apple Mail . These were also deleted from Thunderbird (2 Gmail accounts) on our PC. We recovered the emails, in the process having to change my Google Password. Whilst the deleted emails returned, one Thunderbird Gmail account was not receiving new incoming emails. (one account is) The emails are arriving as normal into Gmail. After various unsuccessful attempts to to connect to the server I deleted the defective Gmail account from Thunderbird, using the Red Button in account settings, hoping to then be able to reinstall it as a new account. When I attempt to reinstall the now "deleted" account I get the yellow "Unable to log in at Server" message. . The password I am using to add the account is the same as the one I use to sign into that account on Gmail (set on Monday), but it does not seem to be working on TB. I tried the trick of not putting in the password when setting up the new account but this did not work either. I am using TB 140.6.0esr Any suggestion please John

Several days ago we inadvertently deleted batches of emails from our two Thunderbird Gmail accounts on our PC and Apple devices. The lost emails were duly recovered but only after having to change my Google password. However one of our Thunderbird Gmail account will not download any new messages coming in. Ultimately we deleted that account from Thunderbird, intending to reinstall it. We deleted the account by pressing the Red button in account settings. We confirmed that messages are received to Gmail's Web page Inbox Now when I attempt to reinstall the account and press Add Account, I get the UNABLE TO LOG IN AT SERVER MESSAGE shown below. The "Your Full Name" I am putting in is the name on the Google account deleted from Thunderbird, and the password I have tried is my new Google password. I have tried the process of not adding in the password until requested to do so but this did not work either. Any suggestions please?

I'm using Thunderbird 140.6.0esr (aarch64) on a 2024 14" MacBok Pro running MacOS 15.7.3 (24G419).

I manage fourteen email addresses, with most of the traffic going to one primary account, either by direct addressing or forwarders from others of the addresses. Maybe not the most efficient setup, but it means I don't have to scan 14 different inboxes to find the messages I most need.

I currently use ±89 filters on this primary account to file messages in a LOT of mailserver-based folders, and a few folders on the laptop. ±90% of the traffic gets filed in server-based folders so I can use any device to access message history. (I should probably note that these filters and message-threading don't always play nice together.)

For a long time, one of the message filters I'll call "Filter BS" successfully filed specific messages in "Folder BS," a server-based folder 2 levels below the inbox. Folder BS also has 2 levels of sub-folders within it for annual and monthly filing.

Some time ago, I began to have problems with messages of many kinds (subjects/sources/etc.) going missing. Eventually, I searched and found them in Folder BS. In response, I deleted Filter BS, looked for but didn't find other filters responsible for these unexpected results, and managed incoming BS-related messages manually. But despite Filter BS having been deleted, non-BS-related messages still get "lost," meaning incorrectly filed in Folder BS, which is acting like a rogue black hole, sucking up everything that gets too close. I have not been able to identify any criteria for what turns up in Folder BS beyond "lots of stuff that doesn't in any way belong there."

Speculating that something's "off" with the BS folder's directory in a way that would be nearly impossible to fix, I'm trying to figure out the least inconvenient, least risky way to solve the problem.

Not knowing other ways I might compound the problem by making big moves with the MANY messages archived in the BS folder's 7 annual subfolders and their 12 each subfolders; and not knowing how to back up server-based in-box sub-folders, I'm stuck at an impasse.

How should I proceed?

Thanks in advance for any input.

I changed my Windows 10 Thunderbird password 3 weeks ago. Every day since then I have not received a single email on my S23 Samsung cell. When I go to log into my Micros account to enter my password I do not have and cannot add or replace an old password. How about I make a donation to Thunderbird for an answer that works?

While reorganizing and renaming a local mail folder it has become inaccessible from Thunderbird. All the other folders are fine.

The folder name is BSW and the BSW file is present, so are the .msf and the .sbd. 1. I tried repairing the folder, no difference. 2. I've tried shutting down Thunderbird, deleting the .msf and restarting. No change in behavior but the .msf file is recreated. 3. I tried shutting down Thunderbird and renaming the files. No change.

Name Thunderbird Version 140.7.0esr Build ID 20260109054016

Is there another way to get Thunderbird to access the folder?

Dear community members, Since receiving the Thurderbird release 140.4.0esr on Oct 14th, I have not been able to send email from any of my accounts (2xIMAP and 3xoffice365 through OWL). Nothing has changed in the account settings. Receive works ok. The usual easy fixes do not seem to work (restart, firewall switch-off, etc.). Any ideas beyond having to rewind to an earlier version and rebuild the whole thing (hopefully not!)?

Version 140.4.0esr Build ID 20251010020716 User Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:140.0) Gecko/20100101 Thunderbird/140.4.0 OS Darwin 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:30 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6020

Thank you for your help! Heli

I'm using the latest version (145) and I've setup my office 365 email account. I'm trying to setup my calendar account as well but when I enter location, username and password it says that my credentials were not accepted.

I assume this means that TB is using legacy un/pw authentication which is no longer supported instead of OATH2. There is, however, no option to select OATH2 in the calendar setup process (like there is for email).

Are office 365 calendars supported by TB 145?

Hello, My SMTP server uses Let's Encrypt certificate. The website with the same domain has no certificate. Thunderbird refuses to connect to my SMTP server. Test connection to the server (STARTTLS) in account settings sais "The secure connection to the server failed" (or similar. I see bg localization). Another server with Let's Encrypt certificate. Test pases. Clicking View certificate shows webserver cert (from DigiCert Inc).

I can't send emails! :)

Regards! Valentin

Hi All,

Just wondering what the roadmap is for multisearch functionality?

I might be a bit dim, but how do you actually search the support forums, as I suspect that this question has been asked before. There are no results returned for multisearch or RFC 7377 or ESEARCH.

Also is it possible to return search results as a vertical list instead of tiled responses, there's a reason why google doesn't do this.

I was working with thunderbird today. Was in a specific email folder I had named "reference" that I use to store various emails, probably around 50 emails in there. Suddenly they all deleted from the folder as I was watching the screen. Checked spam/trash folders and nothing. Also logged into my webmail provider and nothing there either. Any idea what could have happened here? They just seem to have literally vanished. Have used Thunderbird a number of years and never experienced anything like this.

we are unable to sign into tundsrbird using correct creditials. we worked with geek squad and they senr our mail to webnet. the tech told us we would not lose any email that were in thuderbird. when we ckecked they were all gone. there is very inpotant information in there. We would like to restore thunderbird and retrive our lost emails.