Thunderbird Community Forum

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?

I have a professional email address and a gmail address configured correctly in thunderbird. I also have a number of google calendars configured in lightning using the built-in google calendar support (i.e., I am not using the old google calendar plugin). Until recently, when I received and accepted a calendar invitation sent to my professional email address, thunderbird would ask to which calendar I wanted to save the invite. I would select the calendar I wanted and it would be saved appropriately.

A week ago, I created a new google calendar and added it to thunderbird/lightning using the built-in google calendar support. Now, when I accept a calendar invitation, it automatically goes to the new calendar (which is generally not appropriate) without asking me to choose. Furthermore, I am unable to edit these calendar events to change the calendar they are associated with. I have checked the properties of both the new and old calendars and they look the same.

The only seeming solution I found was to make the new calendar read only and disassociate it from an email address, and then undo both those options. For the time being, this operation seems to have gotten back the option to select which calendar invites are saved to. But I would still like to know if this was the correct solution and better understand how thunderbird chooses to save event invitations.

Hi there! I and my colleague encounter some bugs with Thunderbird and we would like to seek your advice in regards of the issue.

1. <user a@citizen-systems.com.hk> was supposed to get a cc copy of the email sent by <user b@citizen-systems.com.hk> at Mon, 12 Jan 2026 09:35:19 +0800 but it never reached. The receivers, namely <user c@systems.citizen.co.jp> and <user d@citizen-systems.com.hk>, however, were able to get the mail. <user d@citizen-systems.com.hk> and <user a@citizen-systems.com.hk> are working at the same office and under the same network. Network provider checked the protocol, router, traffic and firewall are working as normal.

2. <user e@citizen-systems.com.hk> found a number of emails that she kept at "Inbox" disappeared on 12 Jan 2026 morning +0800.

She is unable to find it anywhere at her whole mailbox but has to ask the senders to resend them to her.

It would be very much appreciated if you can check and advise how to prevent the issue from happening again.

(PII redacted by moderator)

Window 11 desktop. Just downloaded and installed Thunderbird. Unable to type anything in to Calendar . Can only create event and that is unable to pick a time of the day just ends up at the top

TB 140.7.0 32bit, Windows10 64bit

My email provider implements black-box spam processing, with deemed spam redirected into a "Spam" folder at the server end which by default is flushed every 60 days.

To view all the incoming mail, I now not only need to view the account Inbox as TB presents it, I also need to log in to the provider's Web interface to inspect the account's Spam folder. I'd rather view this Spam folder through the TB interface to avoid extra logins.

So I

(1) Created a Spam subfolder under Local Folders using the TB interface. The Properties function reports its path as mailbox://nobody@Local Folders/Spam (the Inbox path is reported as mailbox://nobody@Local Folders/Inbox). These paths are read-only as presented by the Properties function.

(2) Used the Config Editor to set mail.server.default.check_all_folders_for_new to TRUE.

(3) Restarted TB, verified that check_all_folders_for_new was indeed TRUE.

However, while the account's Spam folder was known to contain 2 entries at the server side, the end-user Spam folder was not populated, whether by way of TB restart or manual invocation of the Get All New Messages function.

Any ideas ?

Thanks.

Thunderbird has managed to keep all the message headers however the body of EVERY email is now empty. I had archives of email going back to the 80's and it's all gone. I tried to import backups again but TB throws away the body of the messages.

Note that there are many different email address formats in use from regular TCP/IP, XNS, UUCP, Mainframe 8.8, and others. The headers are there and show the addresses but the content is totally empty for every message.

Before TB gets a hold of them, I can read them so I know the data is there and it is TB that is removing it.

Please help

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?

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"

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

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