mferguson,
check out - http://www.linux.org/dist/ - for a good sized list of some of the available linux distributions. From there, you can search different distributions based on your business needs. Whether it's security, red hat based, embedded systems or just wanting a game console...
All you need to do is edit the sendmail.cf file and locate the the section that begins with DS and edit as follows:
DShost.domain.com
with the 'host.domain.com' being the fully qualified host name of the mail server that you will be "relaying" mail messages to.
You will need to...
