[Hampshire] Kmail sending problem

I'm having a real hassle getting kmail on my laptop to send emails.
Situation is:
desktop: kmail 1.13.5 on kde 4.5.5 on ubuntu 10.10 - works
laptop: kmail 4.7.0 on kde 4.7.0 on archlinux - fails

Both receive mail fine, but the laptop won't send it. The send accounts
are setup the same. However when I send on the laptop it just puts it in
the outbox and that's it. It doesn't even ask me for my password for the
smtp server. There's no errors when I run it from the command line,
there's no indication that kmail does anything when I click send, other
than move it to the outbox.

Any ideas on solutions or even just what else I can do to debug this.

Thanks,
Leo