File location of Mail app in Windows 10?

I want to get the right click > send to > mail receipient functionalilty working in W10 and to do this I need to set the file association for the .mapimail extention.

Anyone know where I should set it to (the location of the Windows Mail app) please?

Just figured I don't need to change the file association but would still like to know how to get the send to email recipient function working in Explorer.

Anyone?

All I see is this and yes, defaults are set.