Thunderbird Community Forum

Around early December 2025, right after a new Thunderbird release (I forget the exact version number), there was a change in Thunderbird’s behavior when I click on “Write new message” on Thunderbird’s jump list for its pinned icon on my Windows Taskbar.

In the past, Thunderbird would simply open the composition window by itself and I could get right to typing the new email.

Now, however, after the early-December release, when I click on the same jumplist shortcut, Thunderbird opens BOTH the composition window AND the main Thunderbird program window along with it.

Is there a setting (maybe in about:config?) where I can revert Thunderbird to only opening the composition window?

When I edit a Sent Email as "Edit As New Message", I usually change the subject line. I do this with the hope tthat his new message I am sending becomes a new thread. Unfortunately, it shows up as a thread under the original email, which I edited

How can this be fixed?

-- Mahesh

I'm looking for a developer/programmer with experience in building Thunderbird extensions. I have an extension in mind but need somebody to build it for me. I would pay for the effort--on successful implementation. Please let me know if you know anybody who would be interested in a small project. Thanks.

I have the same original problem as https://support.mozilla.org/en-US/questions/1508740 , and from the same time period, but across 4 of 5 email addresses, with additional problems. All given answers then & now on this website have completely failed me.

I have 4 emails on the same server, which use IMAP, so there is no way for me to adjust any msg retrieval settings, because they don't exist. Surprisingly, one of these 4 emails actually does work in sending & receiving, but I got different error with it, just now! I also have one gmail affected by this original 2 year old problem, as well.

Closing program, restarting computer, and downloading TB updates all do not work. I uninstalled/reinstalled TB, and all of my profiles & emails were surprisingly intact with no deletes (yes, I backed them up in another folder first), and the problem persists upon reinstall of TB, on the exact same emails as the original problem. Antivirus & firewalls are off. Server said it wasn't them. I'm using Windows 11, McAfee antivirus, and the newest TB dld is Eclipse.

There is no distinct alphanumeric error message for the oldest problem, just the usual "Login to server with username failed. Retry/Enter New Password/Cancel." All passwords are correct. None of my passwords are "saved" in the TB program, and I'm having trouble locating where to tell it to do otherwise.

Screencap and copy/paste attempts to grab second error message failed, but it looked like "RETR failed, one message expunged." So far, it's a one-time error, which I can live with. All emails for that ONE working email are fine.

When I attempt to sign into Google, it takes me to a troubleshooting page https://support.google.com/accounts/answer/32050?hl=en asking me to clear cache & cookies, if I'm using Chrome (which I'm not), instead of just a login to retrieve my gmail.

My emails have been sitting on the servers for 2 YEARS and I am at my wits' end - please help!!!

I'm about to travel for over three weeks, and I'll be paying for internet usage by the MB most of the time. When I check messages in Thunderbird, I'd like to prevent remote content from loading - I don't need to see all those images and such during that period. The global "Allow remote content in messages" setting is already off, but I have many "exceptions", and I don't want to just delete all the exceptions and start over allowing them one by one after I get home. Ideas?

Hi,

I do like Thunderbird but there are a couple of things that i'm finding it frustrating to work with and wondered if someone could provide some help?

So I use quite a lot of nested folders, sometimes up to 5 levels deep to keep things organised. Eg:

I a sub folder structure like so:

Trips - -Asia 2025 - - - -Hotels - - - -Flights - - - - - -International - - - - - -Domestic - - - -Parks - - - - - -Park 1 - - - - - -Park 2 - - - - - -Park 3 - -Europe 2025 - - - -Parks - - - - - -Park 1 - - - - - -Park 2

I'd like to be able to be able to select a top level folder (such as Asia 2025) and see all the messages in it and all it's subfolders. Effectively ALL the emails relating to the trip. Is there a way to achieve this?

Second issue: I have a saved search folder called Flagged. Right now I have to edit the properties of the saved search, then click "Choose" and manually tick each folder / sub folder I wish to show flagged messages for. I know I can select the first, select the last, press spacebar to toggle those folders. But it doesn't expand subfolders, and it means that when I add more folders (which I do very very often), I have to remember to manually update the list of selected folders (on 2 machines too as i have this account set up in 2 places). Is there a way to just select a parent folder (in my case i'd like to just select the account itself) and have it automatically include everything below that. Then I don;t need to update or change it as my folders change.

Surely both of these suggestions are sensible and would increase the usability of Thunderbird.

Also, how can I find out what folder a message is stored in from the message in cards view, the message detail panel itself or the right click menu of the message card?

Thanks, Neil

For some time now many users have actively been requesting a domain based filter in tbird's incoming mail system. Is there some reason why Mozilla considers this the ultimate sin or such? I know that with a few email accounts across different servers not all of them allow me to request the filtering from them. Why not just make an all account filter for the program that refuses to accept anything from "@digitalvoice.skin" if I enable it? It would simplify my daily mail load. I would certainly not worry too much about it deleting things I actually want that are coming in on a daily basis such as this picture:

Help, please! I have a twc.com account operating with Outlook 2007 on an old Dell Win7 laptop. It works great but too many websites refuse to recognize the Win7 machine, so I had to "upgrade". I just got a new Dell Win11 laptop and installed Spectrum email to access twc.com. So far, so good. But I need to access the hundreds of email files and folders from the old Outlook-based twc.com account. Can't export them to Spectrum.net as .pst because only Outlook recognizes that file extension. I do not want Office 365, so I tried installing Office 2024. But it's bundled with Office 365. I even installed an old version of Office 2010. When I tried to set up email with twc.com, I got a popup telling me that I had to get Office 365 to do this. Diabolical.

Enter Thunderbird. I downloaded and installed Tbird. I then attemped to use Tbird to be the client for twc.com. I've tried for several days with no success. First I had Tbird search for my twc.com account. Tbird said:

IMAP Incoming: IMAP, SSL/TLS mobile.charter.net Outgoing: SMTP, SSL/TLS mobile.charter.net Username: [edited]@twc.com

Results were quite different from what Spectrum had told me by phone (see below) but I tried this anyway. Got an error message: "Cannot find the server." etc.

So I tried manual setup using the information provided by Spectrum, as follows:

[edited]@twc.com incoming mail.twc,com outgoingmail.twc,com incoming port 995 outgoing port 587 security type TLS

Got the same error message: "Cannot find the server." etc. I then tried half a dozen different changes: change the security type, etc. Nothing worked.

I really need to succeed with this so that I can access all my email files and folders on one computer (the Win11 model). Any suggestions will be much appreciated.

I don't want to save my password in thunderbird, I choose to enter it manually, sometimes I open thunderbird and cancel the request for it to download messages, I have it set on "not to check mail when opened". but i have to set it on check on open just to get the dialog up, other wise the get mail button doesn't work. ie: 140.7.2esr eclipes Please Help Thanks Scott

2 mails n’apparaissent pas dans la boite de réception, mais ils sont dans "tous les mails" de ma boite "Pro" (Google) Je les ai envoyé depuis ma boite perso ( Free), ils ne figurent pas dans les envois, je les trouve en faisant une recherche, mais sans savoir s'ils ont été envoyés .. Et dans la recherche je trouve plusieurs fois le même mail, l'adresse n'était pas bonne (???), je ne sais pas s'ils ont été envoyés plusieurs fois ... ce qui n'est pas agréable pour la personne qui reçoit!!! Merci de votre aide! Olivier

I bought a new computer, when I set it up one of our email accounts populated (X@cox.net)but the other did not (Y@cox.net). We get our email through yahoo and I can find the mail in Yahoo for Y@cox.net. The emails are showing up on my phone so something is working. how do I get it to populate Thunderbird?

(PII redacted by moderator)

Opened up a Microsoft Office 365 account for emails. Everything worked yesterday. Today I turned my computer on and emails downloaded. Later I tried to send an email and it gave me an error message: Enter your password for [edited]@thechartstore.com on outlook.office365.com: I re-enter the password and it still will not send. I checked to see what password is saved in Thunderbird and it is the correct one. This email is working: [edited]@mymetronet.net for correspondence via email. Thanks for any assistance.

My sent folder used to work fine. I have an IMAP account. Everything else seems to work fine. However, when I send a message now, it doesn't get put in the sent folder. The weird part is that when I look in the K-9 app on mobile, the messages are there in the sent folder. It's just in TB that it seems they aren't syncing anymore. The messages just stop on 2/14.

I did research and messed around in the settings. It is subscribed, I didn't change anything to make it not work. The messages it seems should be sent to the folder (and it seems they are, TB just won't see them). I've removed and added the account again, updated TB, restarted it, etc. Nothing worked.

Any suggestions? Has this issue happened before? If you need any more details, just let me know.

I'd like to receive Thunderbird's calendar alerts once and only once; if I'm not at my computer I don't want to keep hearing them over and over every 10 (?) minutes until manually dismissed. I haven't been able to find any setting (including in about:config) that turns on/off the repeat or sets the timeout between repeat alerts. Is it hardcoded? Or is there somewhere it can be changed? Thanks!

I successfully imported the self-signed CA certificate into thunderbird. Then I tried to import the p12 S/MIME client certificate and this error message popped up (cf. screenshot below).

However, I checked the client certificate and it seems fine:

1. openssl pkcs12 -in smime-client-certificate.p12 -info -noout

Enter Import Password: MAC: sha256, Iteration 2048 MAC length: 32, salt length: 8 PKCS7 Encrypted data: PBES2, PBKDF2, AES-256-CBC, Iteration 2048, PRF hmacWithSHA256 Certificate bag PKCS7 Data Shrouded Keybag: PBES2, PBKDF2, AES-256-CBC, Iteration 2048, PRF hmacWithSHA256

1. pk12util -l smime-client-certificate.p12

Enter password for PKCS12 file: Certificate(has private key):

   Data:
       Version: 3 (0x2)
       Serial Number: 1 (0x1)
       Signature Algorithm: PKCS #1 SHA-256 With RSA Encryption
       Issuer: "..."
       Validity:
           Not Before: Thu Feb 19 13:32:18 2026
           Not After : Sun Feb 17 13:32:18 2036
       Subject: "E=user@example.com,CN=user@example.com,
           O=example.com,ST=...,C=..."
       Subject Public Key Info:
           Public Key Algorithm: X9.62 elliptic edwards curve public key
       unknown SPKI algorithm type
       Raw:
           69:58:ee:5d:45:3f:10:d9:bb:8c:a3:b6:a5:c6:16:a6:
           53:78:65:77:73:5d:e0:6f:60:df:2c:32:f3:c2:e2:58
       Signed Extensions:
           Name: Certificate Basic Constraints
           Data: Is not a CA.

           Name: Certificate Key Usage
           Usages: Digital Signature
                   Non-Repudiation
                   Key Encipherment

           Name: Extended Key Usage
               E-Mail Protection Certificate

           Name: Certificate Subject Key ID
           Data:
               99:8a:6d:e4:ec:3a:25:5d:ad:26:a0:36:e1:da:a2:ea:
               bc:88:79:50

           Name: Certificate Authority Key Identifier
           Key ID:
               f5:6c:37:9a:37:d1:81:43:d3:54:3f:b9:33:23:85:c1:
               7e:17:73:88

           Name: Certificate Subject Alt Name
           RFC822 Name: "user@example.com"

   Signature Algorithm: PKCS #1 SHA-256 With RSA Encryption
   Signature:
       44:3a:5e:d7:44:51:f1:3c:a3:80:d8:54:f4:9c:d8:0b:
       ...
   Fingerprint (SHA-256):
       88:95:7A:DF:A5:7C:D1:E8:A5:55:A8:18:BD:BD:7D:92:1F:7D:6E:17:26:68:39:84:26:F3:F6:F3:4A:5C:56:90
   Fingerprint (SHA1):
       72:83:D0:13:C9:C9:AD:46:CA:C3:73:66:9E:79:5B:5C:3B:2E:81:47

Key(shrouded):

   Encryption algorithm: PKCS #5 Password Based Encryption v2 
       Encryption:
           KDF: PKCS #5 Password Based Key Derive Function v2 
               Parameters:
                   Salt:
                       dc:f9:bf:4a:80:e1:7c:4a:b4:f5:52:6b:9b:d5:75:ad
                   Iteration Count: 2048 (0x800)
                   KDF algorithm: HMAC SHA-256
           Cipher: AES-256-CBC
               Args:
                   04:10:0d:a4:96:03:00:2a:d5:a6:fe:d3:6c:a5:d0:12:
                   67:b3

What is going on and how to troubleshoot this issue as there is no logging about this matter into /var/log/syslog?

Environment: - Ubuntu 25.10 - thunderbird 2:1snap1-0ubuntu3

The command STAT did not work. Failure at fetching of message regarding numbers and sizes. E-postservern mailin.telia.com answered: Invalid command; Valid commands: CAPA, DELE, LIST, LAST, NOOP, RETR, RSET, STAT, TOP, UIDLorQ UIT.

I have a calendar in thunderbird that synchronizes with my Synology calendar. How can I open the url, user name and password or delete the existing link to my calendar and make a new one which references my synology url etc.