Well, I cant really comment on this one. My only email experiences is Exim (when I use to run a cPanel server), Postfix, and Sendmail. Postfix is really stable and secure, and if you are using Fedora, Red hat, or Centos. You can install it right from yum. I wrote a guide about installing Postfix you can view it here.
http://www.linuxservertalk.com/forum...hread.php?t=13
