eM Client takes over default mail

I have Office installed on my work PC. Running Windows 11 Pro 25H2. As such Outlook (Classic) should be my default mail. I use eM Client for all my private mails.

When I, for example, click on the email button on an app (office or otherwise), eM Client now takes over, so when I click on that button, the email opens in eM Client with the file attached.

On installation (yesterday), I told eM not to set itself as default app.

If I look at the default settings for programs and extensions, eM Client is nowhere to be seen.

I uninstalled eM Client yesterday and reinstalled it. This fixed the problem.

Until just now. eM Client has again taken over as default mail program. I have not changed any settings and if I look at the default apps and extensions in Windows, eM Client is nowhere to be seen.

Ideas to resolve this?
Thank you!

I made eM client my default email client but the reverse would apply to you. See this Help article on Outlook. See if this would work.

if you’re looking to configure mailto: links you’ll need to just set emclient for that default.

Hi,
The problem is that the standard methods are ignored. mailto: is already set to Outlook. Yet eM Client still takes over.
All the configurations look to be correct.
It also worked correctly after I had removed and reinstalled eM Client. At least for a day. Then eM Client took over again. With no apparent changes in the Windows settings.
As such it looks to me to be very much an issue with eM Client rather than a Windows configuration issue.

This is what I see if I select Settings / General


…yet it behaves very much like it IS the default mail handler.

Check your operating system’s default application for mailto:

Yup, did that before posting. It says Outlook.

that’s interesting b/c I told emclient that i wanted it to be the default and it didn’t change that particular default… it kept going to Outlook until I manually changed it to emclient.

As @Spiffyfunnel says you have to make sure MAILTO is set in Windows as per @Gary post below from the following thread.

If you have done that already “and rebooted”, then you have some sort of Windows registry issue or a problem with your user profile in some way. See this thread below for more information how to fix if still a problem.