I'm having a problem with FileMaker 16.01 talking to Window 10 Mail with one of my clients. I've checked the installation (both Windows and FM are 64 bit), and checked the Mail default and the Mailto default, and both are pointing to Mail. I'm still getting an error when trying to send Mail (see attachment) that says no default has been set (although it has), and can't figure out what the issue is. The user may only have a 'basic' or 'Home' edition of Windows OS installed, instead of 'Windows Professional' or 'Windows Enterprise' suggested in the FileMaker system requirements. Although FileMaker seems to work fine otherwise with this OS, does anyone know of incompatibilities with the Windows Mail program with FileMaker?