Sorry I guess this is about as fundamental as questions get but I am
totally new to Linux.

Installed Mandrake 9.2. Brilliant ! Everything works out the box - even
my TV card which never worked with Windows.

But if I am browsing with Galleon and click on an email address it
complains that Gnome hasn't set up a default mail client to use in such
situations. I would like to use Ximian. How do I do it please ?