Thunderbird - changing default browser used to open links in e-mail

Edit or create the file

/home/USER_NAME/.mozilla-thunderbird/XXX.default/user.js

(USER_NAME in this path will be your user name, XXX will be random letters and numbers). The following example shows how to change the browser to Mozilla Firefox (i.e. if it was set to something else like Konqueror) and assumes the executable for Firefox is on the path and can be run by the command "mozilla-firefox", this can be replaced by the executable for other browsers if required. Add the following to the bottom of the "user.js" file making sure that when you do this both Firefox and Thunderbird are closed:

 user_pref("network.protocol-handler.app.http","mozilla-firefox");
 user_pref("network.protocol-handler.app.https","mozilla-firefox");