- Open Gmail in Mozilla Firefox.
- Type 'javascript:window.navigator.registerProtocolHandler("mailto","https://mail.google.com/mail/?extsrc=mailto&url=%s","Gmail")' (not including the outermost quotation marks) in the address bar.
- If you do not require a secure HTTPS connection, to Gmail, you can use 'javascript:window.navigator.registerProtocolHandler("mailto","http://mail.google.com/mail/?extsrc=mailto&url=%s","Gmail")' instead.
- Hit Enter.


