Thunderbird & no email associated to perform action error

Updated: November 26, 2021

A new weird little problem has landed into my lap. On one of me Windows boxes, I upgraded Thunderbird, the mail client program, to the new release. I went from 78.x to 91.x, and in the process, I also received a gratis error message.

It would pop up on every program startup, and it reads: There is no email program associated to perform the requested action. Please install an email program or, if one is already installed, create an association in the Default Programs control panel. Clunky language aside, Control Panel is sadly no longer the goto place for default apps in Windows 10/11. Plus, the error shows up during Thunderbird startup. Every time. Let's fix this.

Problem in more detail

Upgrade, launch the program. The error message pops up in parallel to Thunderbird launching perfectly normally, and without any issues. You can close the error box or ignore it, the mail client does its job without any issues. The functionality is not impaired. But the popup is annoying.

Program association

Solution 1: Reinstall & reboot

As the simplest solution, you can reinstall Thunderbird and then reboot, because why make things simple when they can be complicated and require a reboot? Ideally, Windows 10/11 will figure things out on next launch, and you won't see the error again.


Solution 2: File type and protocol associations

Remember my article on how to handle file associations in the modern versions of Windows? Well, now we will have to deal with the schizophrenic default apps interface brought into Windows 10 onwards. First, make sure that Thunderbird is the default mail client. However, this isn't enough.

Default app

Go to the bottom of this page. Here, we will need to check that Thunderbird is correctly assigned all the right file extensions and protocols. First, make sure that under MAILTO, the selected program is Thunderbird. This should be the case, if you set the mail client program to it just earlier.

Default association options


Then by file type, check that Thunderbird is associated with MAILTO, .eml and .wdseml. You may discover that there is no association for .wdseml at all - not showing in the list, or that Thunderbird is not shown or available for this particular file type.

No file type

But then, if you click on the third link - set defaults by app, select Thunderbird, and you will the full list of declared protocols AND file types that the program supports. For Thunderbird, there are four. I found out, on this particular box, the WDSEML association was empty. Well, I selected Thunderbird. After this, there was now a .wdseml association available in the list of file types, too.

App options

WDSEML shows

Now, see if this works, and if not, optionally reboot. You should see no more weird, cryptic and annoying popups. The only caveat, it seems, is that this issue may recur any time you upgrade Thunderbird and/or receive a feature upgrade for Windows 10/11. Because we can't have it simple, can we.


I have to say, I kind of hate errors of this nature. They really don't make sense, and they feel like sloppy coding, on the program and system side alike. Not helping is the mess of file type and protocol management in Windows, which is just too baffling and practical to do efficiently. But hey, modern computing.

Anyway, the important thing is, we came to fix a Thunderbird problem, and that we did. If you see an odd issue during the mail client startup about default mail client association, you have three options at your disposal. Reboot, reinstall and reboot, and then file type and protocol setup plus reboot, or just ignore it. Four options. Four! Did I mention the reboot you will need? Ah. There.