Sendmail Problem

Trying to set up my send mail program on redhat 9

keep getting the following errors when trying to send a message to any address outside my server:
**********************************************
The original message was received at Mon, 23 Aug 2004 22:01:55 -0500
from root@localhost

----- The following addresses had permanent fatal errors -----
luke@altrudev.com
(reason: 550 5.1.1 <luke@altrudev.com>... User unknown)
(expanded from: luke@altrudev.com)

----- Transcript of session follows -----
... while talking to [127.0.0.1]:
>>> DATA
<<< 550 5.1.1 <luke@altrudev.com>... User unknown
550 5.1.1 luke@altrudev.com... User unknown
<<< 503 5.0.0 Need RCPT (recipient)

1) edit the sendmail.mc and edit the line:

dnl This changes sendmail to only listen on the loopback device 127.0.0.1
dnl and not on any other network devices. Comment this out if you want
dnl to accept email over the network.
dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')

add the "dnl" infront of the DAEMON_OPTIONS line to comment out this statement. This will tell sendmail to relay mail across a network instead of just the localhost.

2) You will have to recompile Sendmail to enable

m4 /etc/mail/sendmail.mc > /etc/sendmail.cf

3) add your network# to /etc/mail/relay-domains
If the file is not there, create it.