Thunderbird Community Forum

Thunderbird is not synchronizing with Mailfence. My other email accounts (Outlook, Gmail) work fine. TB connects to them, downloads message headers and displays the number of messages correctly. With Mailfence, the messages stop at "connected to imap.mailfence.com" and stalls there. The message disappears after a few seconds and nothing else happens. This happened this morning when I first launched TB. I then got an update to 128.11.1. No change. I did receive the Windows Update 2025-06 Cumulative Update sometime overnight prior to launching TB.

I am trying to import a backup of my gmail using using ImportExportTools.

What does this error message mean? Is there a corrupt email in my gmail? If so how can I find and delete it so I can complete the import, I think it was close to finishing.

2nd question.... After clicking OK on the error message I can select the local folder it was importing and I can see it is then downloading a range of messages with mention of their labels in the bottom of the window but the labels are not creating folders. Should I expect it to do that?

[Exception... "Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]" nsresult: "0x80550005 (<unknown>)" location: "JS frame :: resource://mboximport/content/mboximport/modules/mboxImportExport.mjs?14.1.7 :: rebuildSummary :: line 706" data: no]

rebuildSummary@resource://mboximport/content/mboximport/modules/mboxImportExport.mjs?14.1.7:706:5 _importMboxFile@resource://mboximport/content/mboximport/modules/mboxImportExport.mjs?14.1.7:415:16

I hope someone answers me in Dutch. I cannot open my mail, because I cannot close the "welkom bij Thunderbird" page, that showed when i opened my mailprogramm. I donated, did not work, still not closing, i started my computer again , did not help. I see new mail is incoming but opening is not possible. I hope that i don't have to install it again.Thank you

Guten Tag, ich arbeite mit Thunderbird auf Linux Mint. Jeweils in den aktuellsten Versionen: Linux Mint 22.1 Cinnamon Thunderbird 128.11.0esr (64-Bit)

Auf meinem bisherigen Rechner begann Thunderbird mit dem letzten Upgrade von Linux Mint langsamer zu laufen. Da ich mir nicht anders zu helfen wusste, habe ich in einen neuen Computer investiert. Obwohl der Rechner jetzt deutlich performanter sein sollte, hängt Thunderbird mindestens genauso wie vorher. Zum Teil ruft Thunderbird auf dem neuen Rechner auch keine neuen E-Mails mehr ab. Ein Neustart korrigiert das zwar wieder, aber beim nächsten Start kann es dann wieder genauso sein.

Alles, was man in den Foren findet, um Thunderbird schneller zu machen, habe ich erledigt. Cache gelöscht, im abgesicherten Modus gestartet (da ist Thunderbird genauso langsam). Auch verschieben von Nachrichten in Archivordner brachte keine wirkliche Besserung.

Ich nutze Thunderbird für 7 Kalender (zum Teil lokal) und 10 E-Mail-Adressen bei unterschiedlichen Anbietern.

Als Add-on habe ich DKIM Verifyer installiert und aktiv.

Ehrlich gesagt, bin ich inzwischen ziemlich verzweifelt, was das Thema angeht. Witzigerweise lassen sich die Entwicklerwerkzeuge nicht aufrufen. Keine Ahnung, ob das vielleicht ein Indiz für den Fehler sein könnte.

Hat jemand eine Idee? Oder noch Fragen?

Herzlichen Dank.

Since Thursday last week, I've not been able to receive or send e-mails.

I constantly receive the error asking for my password. It's the same for my hotmail account and my two gmail accounts.

Please help.

Carol

How do I change the scroll bar width in Thunderbird? I can change the width in W11, but it has no effect in Thunderbird. I am using Thunderbird version 128.8.1esr 64 bit.

Thank you

Thunderbird crashed on me last night: "thunderbird killed by SIGSEGV"

The attached image shows that I'm being prompted for an API key. I'm not sure what that is or how to generate one (I presume unique to me?).

I believe I need one in order to file a bug. I can't seem to circumvent it.

Can anyone guide me in the right direction please?

My smtp account settings are correct yet anything sent is returned. When I go to my webmail account, I have no problem with sending anything. Does tbird have a different setting for SMTO?

How do I create a new mailing list? I'm trying to follow the instructions here, but with the address book open, I don't have "mailing list" as an option under 'File' 'New'. See screenshot attached.

https://support.mozilla.org/en-US/kb/how-create-and-use-mailing-lists-thunderbird

Thanks for your help.

My user upgraded Thunderbird to v136 and no longer can sync his calendar on our IMAP server (Cyrus). When Thunderbird attempts to log into the calendar Cyrus logs an "Internal Server Error" with the detail

May 5 15:11:39 XXXXX cyrus/https[198300]: badlogin: [10.8.0.10] Basic SASL(-1): generic failure: All-whitespace username. May 5 15:11:39 XXXXX cyrus/https[198300]: [10.8.0.10] with "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:138.0) Gecko/20100101 Thunderbird/138.0" via SESSIONID=<cyrus-1746483098-198300-1-4996003587903488780>; "PUT /dav/calendars/user/XXXXX/Default/040000008200E00074C5B7101A82E00800000000E0076891A1BDDB0100000000000000001000000076BAF045101B7D4EA90CA085DF4D7B11.ics HTTP/2" (if-none-match=*) => "HTTP/2 500 Internal Server Error" (stream-id=3; error=The server encountered an internal error.) [timing: cmd=0.000448 net=0.000035 total=0.000483]

The user can access their email so their account username/password is stored correctly in Thunderbird, it's just not making it to the calendar subsystem.

Failure is 100%. The user can access their calendar from the previous version of Thunderbird and by using another app on their phone.

1. Thunderbird was not my default mail client in Windows. When I tried to select it as default it did not appear in Windows' list of applications.

2. I tried to find the my profile and it showed where it was - but that directory did not exist. I finally was able to make a new profile and the directory showed up - but then the default-esr profile disappeared and now I can't find it and neither can Thunderbird. Is there a way to find where it went? I don't believe I delete it, it just went away. This is the message I get:

Your Thunderbird profile cannot be loaded. It may be missing or inaccessible

Have always set up accounts so they download all messages to hard drive.

Since 3/27/25, it is as if it never officially logs the downloads as downloaded, so it downloads each day as if it hasn't been done since 3/27/25, marking all of the messages since then as new.

File is very large so want to try fixing without deleting entire file.

Tried the 'repair this folder' but that didn't work.

Having trouble identifying the exact folder on the hard drive to delete since there are several different accounts in the Thunderbird setup.

Thunderbird started crashing randomly about 2 days ago, however, after restart, it would remain running if I switched to troubleshooting mode. I removed an add-on from Bitdefender in troubleshooting mode.

Today I can't even open Thunderbird-- it crashes on launch. It won't launch even if I hit the Shift key or if I turn off antivirus.

Here is the most recent submitted crash report:

Crash ID: ⁨bp-b52cd345-636f-445a-ab4c-764ca0250114⁩

Can someone please give me guidance on what is going on and how to fix it?

Thank you.

I've been having issues with Thunderbird randomly hanging over the last few weeks. It's always been slow to upload all my gmail messages, so I let it get done with that before I start reading. However, now it randomly decides to hang forever. It generally happens when I delete or move an email to another folder. It doesn't complete the function. I can click on other emails, but it doesn't open them. The UI just sits there with the blue progress bar shimmering away, forever. None of the window control work (File, X, etc.). I have to use the Task Manager to end the Thunderbird task. When I start it up again, the message will be moved or deleted, and I can view more messages until it decides to hang again. This happens about four times per day.

I have an MSI GS75 Stealth 9SF laptop, running intel Core i7, Windows 11 (up to date), and the most current version of Thunderbird.

I didn't see anyone else commenting on Thunderbird hanging frequently, so I'm wondering if it's just me.

I have been having much trouble with Thunderbird. The latest problem is with the Sent folder. When I try to Compact Folders I get the message "The folder 'Sent on Local' could not be compacted because writing to folder failed. Verify that you have enough disk space, and that you have write privileges to the file system, then try again."

I have plenty of disk space and have Full Control. I tried creating a temporary folder and moving all the Sent messages to it, so that Sent had zero messages. I still got the same message. The file listing showed Sent to have a size of 182 MB even though it didn't contain any messages. I've tried deleting sent.msf to force Thunderbird to recreate the index - didn't work. I tried using Repair Folder. That worked, but when I tried Compacting Folders again it found another folder with the same problem. I fixed that one and then it said the Sent folder was bad once again. I'm going around in circles!

I've deleted and recreated scores of .msf files for various reasons, trying to get Thunderbird to work without errors, but as soon as I get one problem fixed, another one crops up. I'd conclude that it's my computer, except that I'm not having any problems with other programs.

Any thoughts on this particular problem or Thunderbird problems in general? Thanks.

It appears that Thunderbird knows how much disc space is required to compact a folder, since it says there is not enough. Could the message say "You must have xxx free disc space" rather than having to use the trial and error method. If this space is 'work space' could Thunderbird be instructed to use a drive other than C: for workspace.