Until today, every time I’ve clicked a mailto link in Firefox, the clunky old Evolution email program has started churning, and I’ve smacked myself on the forehead and cursed as I waited for that behemoth of an application to load. You see, I use the lightweight Thunderbird, which loads in an instant and is as flexible and powerful as I need it to be. So I wait for Evolution to finish loading a compose window, close that down, copy the mailto link into a Thunderbird composition window, and write my email. It’s a pain every time.
One of the RSS feeds I keep an eye on is Linux Journal’s, and an article entitled “Ten Mysteries of about:config” caught my eye there today. It’s a decent little article by Nigel McFarlane, author of Firefox Hacks, which I just received in the mail this week and which looks promising. One of the mysteries Nigel explains is how to set a default mail client in Firefox on Linux (it’s easy enough in Windows because it’s governed at the system level). It takes only three steps:
- Open about:config in your browser.
- Set the preference named “network.protocol-handler.external.mailto” to true; if it doesn’t exist, create it and set it to true.
- Create a preference named “network.protocol-handler.app.mailto” and set it to the path to Thunderbird. In my case, this is /usr/local/thunderbird/thunderbird.
That’s all there is to it. When I did this and clicked a mailto link, a Thunderbird composition window shot to the foreground and I was in business.
Two Ells 
Hello,
I’m a Linux nube and this was a big help. However, I am using Ubuntu and the application file path you provided did not work. After some looking here is the Thunderbird path for Ubuntu 5.1:
/usr/bin/mozilla-thunderbird
I think this is also the general location for most of the applications for any former OSX and Windows users wondering where their Applications/Programs folder went to. Thought this might be helpful. Thanks again.
To add the app.mailto pref, right click -> new -> string
I realise that one can set the desired mail program explicitly but if you don’t do that, how is firefox (Linux) determining the “default” program in the first place – is there a file somewhere (perhaps in /etc) that defines default programs?
Thanks
It works perfectly when clicking on a “mailto” link or “sending” the page, but the option Tools > Read Mail doesn’t work. I’ve read that this feature is only available in Windows, is it true? I can’t believe there’s no way to enable it. There’s always a way in Linux!