Exim will not install or configure on Debian Squeeze

Trying to get ANY light weight mail system on my new Debian 6 Linode.

When I follow the Linode library instructions to install the Exim send-only mail client on Squeeze, I get:

"Could not perform immediate configuration on 'exim4-daimon-light'. Please see man 5 apt.conf under APT::Immediate-Configure for details"

When I try and run "dpkg-reconfigure exim4-config" it says:

"exim4-config is not installed"

If I look at my installed packages list, sendmail is on there but no Exim. Do I need to remove that? I'm trying to consolidate to Linode from Godadday, but can't because I need PHP forms to send mail.