[cobalt-users] Mail Relaying Problem on a RaQ 2

[test <test@xxxxxxxxxxx>]

I'm having trouble with mail relaying.  I have read the Cobalt RaQ.  I
think I understand...

I created an account "test" for a vitual site "site.com".  When I log in
to the RaQ as "test" I can send mail to other domains using
/var/lib/sendmail -v somebodyelse@xxxxxxxxxxxxxxxxxxxx

But, when I try to send mail through the server using Netscape I get the
"relaying denied" error.  I'm connected to my ISP via
"pm2-02.lituus.net"

In Netscape preferences I make these changes:

Email address --> test@xxxxxxxx
Mail server user name --> test
Outgoing mail (SMTP) server --> mail.site.com
Incoming mail server --> mail.site.com

I have an MX record for mail.site.com that points to the RaQ IP address. 

I get this syslog message in /var/log/maillog:

Apr 12 00:13:52 raq1 sendmail[13035]: AAA13035: ruleset=check_rcpt,
arg1=<cobalt-users@xxxxxxxxxxxxxxx>, relay=pm2-02.lituus.net
[207.152.28.46], reject=550 <cobalt-users@xxxxxxxxxxxxxxx>... Relaying
denied   

So the email address I set in Netscape is 1) ignored or 2) not used as
the sender's address, or 3) rewitten to pm2-02.lituus.net.  How can my
clients use Netscape (or any client) to send their outgoing mail through
the RaQ amil server???  I would have to add every possible IP address,
or domain, or network they could be sending mail from?  Doesn't that
defeat the purpose of not having a third party relay.  What if the
client is connecting via AOL?

Thanks!

Bill