southern writes:  

In olden days, when you clicked on an e-mail link in your browser, it had to have an e-mail client to launch. That method doesn't work if you use a service such as Gmail or Yahoo Mail as your main account.

Firefox 3 to the rescue. Watch our video on how to do this tip, then come back here for the written steps.

Go to Tools and options (Firefox and Preferences on a Mac).

Choose Applications.

Search "mailto".

In the drop-down menu Choose Yahoo Mail.

What? You don't use Yahoo Mail?

Open your Gmail in Firefox.

You'll need this string of code to enter.

javascript:window.navigator.registerProtocolHandler("mailto","https://mail.google.com/mail/?extsrc=mailto&url=%s","GMail")

Press add application.

And now when you click an e-mail link, it will ask you which Web mail program you'd like to use.

Webware

note: remove space from javascript code above.