Thunderbird Community Forum

When I click on an email, instead of just showing the email, it sets up a Reply screen showing From me and To Me. At the bottom there is an alert: "A unique identity matching the From address was not found. The message will be sent using the current From field and settings from identity......" (lists my email user name and address). Im not clicking Reply, I'm just double clicking the message to Read it.

Running Sequoia 15.7.2 on MacBook Air. It just started today. I have turned it off and on, no change.

Hi, I dont know what setting I have accidently changed but before I used to double click a new message in my inbox on local folders and now instead of reading it full screen now it wants to send it as an email message to someone!

Any ideas to put it back to just read the email and not compose a message with it?

Thanks.

I dont remember having this 'new message template' thing before when I right clicked on a message in my inbox , maybe thats what the issue is?

Today filtering of new emails fails for all folders. The message is "The message could not be filtered to folder <folder> because adding a message to it failed. Verify that the folder is displaying properly or try to repair it from the folder properties."

This is new. No problem filtering message a few days ago.

Windows 10 laptop PC.

Lots of free space on my local drive where Thunderbird is installed.

Where are these folders stored? I looked in C:\Program Files\Mozilla Thunderbird but I do not see any such folders there. I looked in C:\ProgramData\Mozilla but nothing there either.

Thank you.

I had knee replacement surgery on 10/10/2025 and was unable to access my PC to download email. When I was able to access my PC(physically unable to get to the PC until12/7/2025) email had stopped downloading after 10/27.2025 and many of the ones downloaded were multiple copies of the same text. I decided to just highlight a large group of email and just trash them unread. I have now trashed 5000+ emails and the system will stil not display any after 10.27/2025. I am at my whits end, I am a 78 year old retired non-software engineer and really need some help. This is my primary email account and really need to read what's current.

For 3 days, I haven't been able to access my GMX email account. It tells me every time "Login to the server imap.gmx.com with username '[edited from public] @gmx.com' failed. I hadn't changed anything beforehand and all the entered data is correct. My other accounts like gmail, yahoo, works just fine. Tried installing older versions and still no success. Outlook app works fine either. I'm pretty sure that GMX mail server made some changes that Thunderbird is missing. Please verify.

Best regards

Nilson Xavier

I've been using Thunderbird for years (Windows 11 PC), and all has been working fine as recently as last night. Starting this morning, I continuously get the error message, "Login to server mail.comcast.net with user name xxx failed" (xxx not my actual account name). I've tried the "Retry" and "Enter New Password" options to no avail. I can go directly to the Comcast website, login and get my email that way, but I can't get Thunderbird to login.

To my knowledge, nothing changed between last night and today, but yet something seems to have happened. Any ideas appreciated!

Hi everyone - and big thanks in advance for considering my request: I have/ had windows 11 on my old machine and windows 11 on my new machine; because my 'old computer' is not running anymore at all (liquid damage), I can no longer start Thunderbird and follow the 'export tool function' (https://support.mozilla.org/en-US/kb/thunderbird-export) and thus can only do the manual transfer (https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer); I didn't think that I would need to go through the export tool steps when I saved the Thunderbird profile folder regularly as backup on the cloud; yet when I started Thunderbird on my new machine following the above steps by moving the Thunderbird profile folder manually, the result is that - although Thunderbird is 'running' and the mailbox is functioning properly - the key folders are empty (i.e. the sub-folder structure is completely lost, in fact there are no individual emails at all); the issue seems to be that the size of the Thunderbird profile folder is too large (the "Profiles" folder has a size of 20.5 GB) for doing this transfer via copy & paste of the Thunderbird profile folder from the cloud (I also tried USB) to the new machine; I understand that the size issue via the manual transfer could be 'overcome' just by starting Thunderbird on the 'old machine' and following the above steps explained under mozilla support; yet that's no longer an option; what could I do please?

I have been having using Thunderbird as my email package for over 10 years and lately have been having issues. I was looking to cleanup the install (version 140.5 esr) and noticed an older version of the app still exist on the computer (version 68.4). will deleting this version have any implications. This computer was originally Windows 10 but has been upgraded to Windows 11 when the problems seemed to start appearing.

I'm helping someone with their Thunderbird. She says her address book is dropping street addresses. We went through and found a number of contacts that she had updated but they now seem to be be simply name and e-mail address. The only thing I found was the majority of addresses are in the "Collected" group if that matters.

Any hints or tips on this?

I gave up on Outlook after a zillion years using it. When I reset my O/S (win11) I had to reinstall Outlook from Office, all paid up and legal. Nothing but problems trying to get my backed up PST file from previous Outlook. System kept trying to get me to subscribe to Windows 365 crap. I had standalone 2024 version of office. When I installed Thunderbird (I have it on laptops and other computers), I entered my email and voila, in about 1 minute I was sending and receiving emails. I had spent 6 hours on Outlook, even using AI (Copilot) to help me. I was SO IMPRESSED, that for once I donated to Thunderbird, $30 CAD.

Now, I used Mailstore to get my pst file, something I could NOT GET OUTLOOK to do, and have it available to export to Thunderbird, or for TBird to IMPORT from the pst. Neither one worked, telling me that TBird didn't have a profile for the transfer, or some such notation.

Any help would be appreciated. Like many of you, my whole communication life is in those emails (I have about 40 folders where I saved stuff).

I have a problem with Thunderbird on Kubuntu 24.04.3. The drag and drop of mails from inbox to TB-folders stop working after a while. It always happens when I minimize Thunderbird and maximize again, then the drag and drop has stopped working. I have also seen it if I for instance make a new folder, then it also stops working. It has been going on for a while now, at least the last 3 month. I have automatic update on, so I an running the latest version right now 140.4.0esr (64-bit).

Hello,

I have a MacBook Air M2, and I'm experiencing energy usage issues related to Thunderbird. This has kept happening for a long time now actually, surviving through at least two Mac OS updates, and a huge number of TB updates. Everything's up to date. I tried to follow this: https://support.mozilla.org/en-US/questions/1269944 and this: https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems?_gl=1*86dj4d*_ga*MTkzNzQ0MjA3MS4xNzYyOTY4OTMx*_ga_2VC139B3XV*czE3NjMzMTM3NDckbzIkZzAkdDE3NjMzMTM3NDckajYwJGwwJGgw but didn't succeed. Actually, in my case, the issue is more noticeable: I normally have TB open in background - sometimes everything's fine, and the battery goes down as normal, while sometimes instead the battery drops quickly, and checking in the Mac activity monitor I can see that the CPU usage of TB is totally abnormal. When this happens, I can actually see the activity bar in TB being live (bottom right corner, as it happens when TB is checking for new mails), but never disappearing. When I notice it, I just reboot TB, and the bar shuts off as normal after a quick mail check. Moreover, checking the 24hr energy usage by app, TB is often on top with nonsense values.

I tried multiple times to rebuild the database, and do most of the tricks suggested, but didn't fix. Yes I have a huge mail archive, but the problem is not the standard management of this database: basically it seems that every now and then, TB decides to run some activity which it gets stuck in, and this kills the CPU.

Thank you in advance for your help!

Hello Everyone,

In Thunderbird, I'm receiving a notification that I had a new email, but then it disappeared and didn't appear in my inbox. It reappears after about an hour. (but i'm not sure if i'm receiving all the email email or not) This happened after updating to Windows 11.

There is enough space. I uninstalled and reinstalled. It's up to date. The emails are not in any other folders. The same problem occurs on the website. Everything is working OK with my company email address; the problem only occurs with my personal email address, and I use both on the same laptop. This issue happens with all received emails from all email providers, such as Gmail and Hotmail..etc. Can anyone help me with this issue?

I have been setting up laptop for a local sports club. The underlying email account is a gmail account and I have used Manage Identities to set it up so that by default emails show as coming from the club's domain-related account, e.g. manager@sportsclub.uk. All seems OK; however, the email one receives from the account shows the correct signature, but still as coming from the gmail account Curiously though, if one hovers over the email address it shows the name of the 'manager identity' even though the display shows the name of the underlying gmail account. Everything is set up exactly as I have in my personal Thunderbird account which has several identities and all work as expected. The only difference is that my email account is a Plusnet one. So I assume that it must be a feature of gmail. Does anyone know if that is the case and what one can do about it?

Hi I have 2 gmail accounts set up in TB. Neither of which are my daily accounts.

I've noticed that both of them put a copy of any email I receive into archives, as well as my inbox. I've checked my account settings & they're identical to those of all my other email accounts.

Not only that, but one of the accounts puts every email I receive into inbox, archive AND archive for that email address, so basically, I'm getting 3 copies of all those emails.

What I want to happen is what happens for all my other emails. They arrive into inbox & I put them in local folders/delete as appropriate

All help gratefully received Thanks

Why does Thunderbird now label the Junk button as Spam, even through I have no Spam folder -- just a Junk folder? Also, in Settings Junk is now labeled Spam?? Screenshots attached.

I am using Thunderbird 115.5.2 (64-bit) on an older iMac on OS 10.12. I have four email address accounts, all gmail, and using POP. I have stored emails I wanted to keep in sub folders in Local Folders. This has all worked well for years.

Yesterday I lost lost all content from some of the subfolders in Local Folders, while some retained some content and a few seem intact. I also lost most emails that had arrived in the inboxes in the last week. The folder pane still shows the accounts, with their own set of folders. As usual, the inbox folders are highlighted with the number of new emails downloaded from the Gmail server to each address, but I can not see them in the message pane, or find them anywhere else. I sent a test message from one of my addresses to another – It didn't show as sent in Thunderbird, but did go through the gmail server and the message count of downloaded messages on the recipient address went up by one, but I couldn't see the email. Then I tried clicking on the folder "properties" then 'Repair Folder' but nothing happened, although the information on that window showed the number of messages and MB that I would expect to be in that folder, rather than what was there, which presumably means they may still be in there somewhere? I would be very grateful for help – I'm not tech savvy and feeling completely lost.