Default mailto application on Fedora 17

[Dave Close]

I'm running Fedora 17 with the KDE desktop. KDE's system settings
("control panel") claims the default mailto application is Kmail. And,
since Gnome is still present, I see that it thinks the default mailto
application is Evolution. I don't see anything in /etc/alternatives
that seems relevant to a mailto handler.

Firefox says, "Firefox normally uses your operating
system's default mail program to send an e-mail message."
<http://support.mozilla.org/en-US/kb/change-program-used-open-email-links>)
But Firefox says the default handler is Thunderbird. Where the hell is
Firefox finding that value? And Firefox doesn't offer either of the
other two "defaults", Kmail or Evolution, as options (except through
the "other program" mechanism).

Can anyone explain what's going on?

I'd like to change the mailto handler. But I need to pass some arguments
to my program and Firefox doesn't offer that ability itself. To get that
ability, I need to be able to change the system default so that Firefox
recognizes the change. But where is Firefox finding the "default"?
-- 
         Dave Close, Compata, Irvine CA       +1 714 434 7359
       dave at compata.com              dhclose at alumni.caltech.edu
   "The world will little note nor long remember what we say here."
                   -- Abraham Lincoln, Gettysburg, 1863