--- ./defaults/pref/firefox.js.orig	2007-02-20 05:25:52.000000000 -0600
+++ ./defaults/pref/firefox.js	2007-03-07 13:13:55.000000000 -0600
@@ -365,6 +365,7 @@
 pref("signon.prefillForms",                 true);
 
 // We want to make sure mail URLs are handled externally...
+pref("network.protocol-handler.app.mailto", "/usr/bin/thunderbird");
 pref("network.protocol-handler.external.mailto", true); // for mail
 pref("network.protocol-handler.external.news", true);   // for news
 pref("network.protocol-handler.external.snews", true);  // for secure news