Email Server and DNS

[<rwebb () ropeguru com>]

So I figured a little break from the NSA was in order.

I am looking for some info on current practice for an email server and 
SMTP delivery. It has been a while since I have had to setup an email 
server and I have been tasked with setting up a small one for a 
friend. My question centers around the server sending outgoing email 
and the current practices requirements for other servers to accept 
email Things like rDNS, SPF records, etc...

I am pretty much set on the issue of incoming spam and virus. Probably 
overkill but it is checked at the Sophos UTM firewall and at the email 
server itself.

Thanks,

Robert