Relay with Firewall

[Chris Morris]

I using Checkpoint with my Linux box in a DMZ. I have a problem where
Sendmail will not accept email for outside side unless I have the internal
DMZ ip address as a relay accept. Only thing is that this also opens up my
server to spam relay from the outside. I tried to use DRAC for pop before
SMTP, but can't seem to get it to work that way either. I'm getting:
g5BDUL731280: ruleset=check_rcpt, arg1=<jcmorris_99 na yahoo.com>,
relay=[192.168.10.1], reject=550 5.7.1 <jcmorris_99 na yahoo.com>... Relaying
denied. IP name lookup failed [192.168.10.1]

I've checked DRAC and all seems to be working there. I have the firewall not
allowing email from the outside for send right now, but seeing that I need
to have a on the road access this is a problem. any clues as to how to
figure out if DRAC is working right or how to allow relay without using the
192.

Thanks all. Chris Morris