But...that's what it is, in Windows 10, essentially...
Also, they can have the "most obvious" name, because they were first, and set the standards - literally.
Actually, windows 10 has a built in mail client, that I think is called... Mail ?
but you don't need to look for it somewhere on internet, so it does not matter it has so common name, because it is built in unlike whatever will be named new matrix client you have to download to your mobile device