Set Gmail as the default e-mail client in Google Chrome
This tip should also work for other webmail providers if you know the correct URL to use.
Source: updates.html5rocks.com/2012/02/Getting-Gmail-to-handle-all-mailto-links-with-registerProtocolHandler (Via)
- Launch a new browser window and open up Gmail.
- Accept the confirmation at the top of the browser window and try out a mailto link. If you should ever need to remove this setting, you can do so via chrome://settings/handlers.