In Windows 8, it’s by default set to use the native Mail Windows 8 app but here is how you can change it.
- Open Control Panel. You can do so easily press Win+X, and select Control Panel from power user menu that pops up.
- Click Programs, and choose “Make a file type always open in a specific program”
- In the next Window, find and highlight MailTo item from the long list of extensions. You should be able to locate it at near the bottom of the list.
- Double click and pick one from the “metro style” popup.
- Pick one from the list and Close. You are all set.