If you're stuck on the ubuntu idea, kubuntu runs kde by default and has
kmail.  I would not recommend it over opensuse.

I'm quite happy with my standard ubuntu install, or was until I upgraded to
the Hardy beta and my window buttons stopped working for a few hours.  That
uses Evolution as it's mail proggy.

I agree with Kurt that Ubuntu has a long ways to go before it's as
consistent as Suse or Redhat.  I think it's worth the effort.

I also run Gentoo, but that's more a distro for masochists.  My mail program
on there is pine and I don't run X.  It will run X fine, but I like
terminals on big screens.

-- 
James McPhee
jmcphe@gmail.com