I-Thunderbird Community Forum

My Thunderbird install updated from 140.13.0esr to 153.0.2esr yesterday and now I can no longer drag and drop any attachment from an email to any folder on my computer. I simply get an error message window with a title of "Error Moving File or Folder" with "Unspecified error" text. See image attachment.

I've tried a variety of folders, including Downloads, Documents, Pictures and other folders on local and external storage devices.

I can save the attachments using the Save All button, or by right-clicking a file and choosing Save As, but not by dragging and dropping as I have done so for years.

I have checked if Thunderbird is running in admin mode, which it is not, but have tested it both ways with the same problem occurring. I have also run Thunderbird in Troubleshoot mode, and the same thing occurs. I tried clearing the startup cache from the troubleshooting page with no change. Restarting the PC did not resolve the issue, and disabling my anti-virus(Avast) also did not make a difference to the issue.

Recently updated to ESR Meadow.

Now when I try to save attachment from an email by dragging and dropping to desktop, Windows pops up "Error Moving File or Folder - Unspecified error" and the operation fails.

And when I try to save attachment from an email by right click > open > Save dialog, the save filename is always "nsmail" but with the original file extension. E.g. a jpg attachment would come up as "nsmail.jpg", and a txt file attachment would come up as nsmail.txt. It does then save it, but why lose the filename?

It used to preserve the attachment filename, I'm sure! And drag and drop to desktop was such a convenient feature!

I have tried in Troubleshoot mode and behaviour is the same. I have tried in Windows Safe mode and behaviour for Save is the same; but drag and drop is completely disabled there (when I drag it, it shows a circle with line through icon).

Is it just me?

I have tried on several occasion to send an email with xlsx attachment and you tell me 'This message does not meet our delivery requirements.' I have sent emails previously successfully to the address without the attachment.? What is the problem?

With 03.04.2026 they began to notice that the attached emails in eml format (the attached emails have attached documents, mostly pdf) sent from yandex mail stopped opening. Everything used to open well. Eml also does not save to disk. If you send the same files via Gmail, everything opens. Program version 150.0.1

Where does Thunderbird put attachments that I open (say a PDF I opened)? Sometimes these documents are sensitive and I want to assure any temporary copies are deleted, either manually but preferably automatically

Will setting "browser.helperApps.deleteTempFileOnExit" to "True" help?

Thank you.

Most attachments come through as application/octet-stream which I should be perfectly able to view via "gnome-text-editor" or "gedit" etc. I want to be given the option to use one of these.

I don't see any mechanism in the menus to allow this, though. The "application/octet-stream" is conspicuously absent from the content-type list, which is absurd since that's what 99% of all attachments are recognized as.

Note that I want this as an *OPTION* to going through the steps of downloading and then viewing the file.

Have been forwarding all my AOL mail to Thunderbird for years without problem.

About 2 wks ago, email with attachments stopped being forwarded. Emails without attachments are forwarded without problem. AOL says nothing changed on their end although I noted that the "Forwarding" tab no longer appears on their mail choice menue.

I occasionally receive HEIC as attachments. Opening the attachment defaults to my Adobe Acrobat which also cannot open HEIC. Is it possible to set the default open to Paint or something in Win11? Thanks.

Opening a PDF from an attachment in TB (version 138.0, Build ID 20250423163813), scrolling to any page, and choosing to print "current page" always points to first page. I tried this from two totally different machines and accounts, one Win 10, another Win 11.

I have an issue when trying to forward an email that contains an attachment. I receive the following error message:

"Sending of the message failed. There was an error attaching the file. Please check that you have access to the file."

I am using Thunderbird version 152 on Windows 10 Pro.

This issue only occurs when forwarding emails with attachments. Other email functions appear to work normally. Has anyone else encountered this issue? I would appreciate any help or suggestions. Thank you in advance.

When I forward email chains containing more than one email, the attachments will not appear for the recipient.

Once when forwarding the same chain a second time, the attachments did then show up.

What happened to the useful top right window box for attachments on my outgoing emails, can I return it? It's gone to the bottom and is really annoying, I mean who decides these useless and unhelpful changes?

Good day,

I am a TB user (for work) and i love it, the main reason being the fact that it's simple, compared to MS Outlook, for example. Easy to use, intuitive for new users, and so on. So congrats to everyone for keeping it simple! :)

Now, an issue i've come across recently. More and more people send documents as .jpeg, pictures taken by smartphones. And, as everyone knows, the recent models have increased the MB of each camera. And most people sadly keep the max resolution, best quality, like you'd use when going on a holiday. But you don't need this when you take a picture of an invoice or a gas receipt. This results in very large attachments, esp. when you add several pics to an email.

The current limit seems to be 25MB (i got this from Google, didn't see any mention of a limit in TB help?!). So my question is simple: can I, a user, increase this limit somehow? Or is it a dev related setting? If users can, please guide me through some options/menus because i haven't found any. I use the latest version, 140.8.0esr. A realistic limit, imho, would be 100MB/email.

Also, kindly please keep feedback on topic, I am not interested in sharing, or sending in any other ways, like wetransfer, google drive, one drive, etc.

Thank you!

I've inadvertently made some change to 'Open with' so that when I add an attachment I can not open it within the email I'm sending. It opens for the recipient but not for me. When I click on the attachment nothing happens. It doesn't occur for all attachments but it seems to be for any attachment requiring 'Photos' as the option to open. Can you help please?

The attachment icon is missing from the message display pane in incoming emails in Thunderbird. Before it was always displayed at the bottom of the window. I have 'Display Attachments Inline' checked and I also repaired the Inbox folder but still no icon visible. I am using the latest version of Mozilla Thunderbird 151.0.

Since the most recent update, Thunderbird doesn't load the email when clicking on the entry in the inbox, and then when double clicking to open in a new tab, the main window is blank with a Loading... text on the top left, and the URL shown above starts with chrome://

Running Thunderbird 146.0

Dear Thunderbird,

I have been using Eudora for 20 plus years and migrated to Thunderbird after Mozilla took it over. After my donation, I have observed that the last update that you have done, has a bug.

I would always detach any attachments on my email and categorize them in my set directories for easy retrieval and I have these files since 1991. Off late when I detach a file it deletes it from the email, and saves it to my attach folder, desingated in the options menu, making my inbox file that I backup smaller and managable on a pen drive too. Now when I detach files, it deletes them from the email but the attach directory is always empty.

Please rectify this as it is causing a lot of files being lost.

-- with warm regards

Kamlesh Barot

Director - VIE Hospitality

"save all" to save attachments stopped working. I tried selecting all and Control C to copy them, and that did not work either. Often need to save multiple attachments since I work from home.

I am not sure if this is an issue that is isolated to the DropBox provider or to all of them.

But the issue is when you have multiple attachments and then try and use FileLink to upload them, it appears like ThunderBird tries to make too many connections at the same time or tries to upload too many of them at the same time because some of them will go through but then all of a sudden an error message pops up for the remaining files that says "Upload Error" Unable to upload FileName to DropBox.

Which you could then right click each item below at the attachments location and Convert to DropBox but you have to do it with each individual file.

It seems like maybe the FileLink feature itself just needs to space out each of the uploads in order to avoid this error but I am not sure.