Email for Home-based Ubuntu Server

I need email set-up on Ubuntu LTS 10.04. It is a Live/Working Webserver! I have one Wordpress Blog which does not send registration emails out. I have Webmin w/ Virtualmin installed. I am not sure if Sendmail or Postfix are prepared yet, etc. I am fearful about creating a SPAM Box, so you must be familiar with configuring a Mail Server, and must instruct me how to prevent SPAM Box from happening! (I don't want the server to be tied up fighting SPAM instead of serving webpages) (is that possible?) Here are some example errors in my [login to view URL] [login to view URL] &[login to view URL] logs: warning: process /usr/lib/postfix/cleanup pid 30820 exit status 1 fatal: dict_open: unsupported dictionary type: mysql (/usr/lib/postfix/[login to view URL] not found. Is the postfix-mysql package installed? I only have $37.20 for this project.