basic sendmail problem

[David Syphers]

I've previously used sendmail in a very simple configuration - it just 
forwards my mail to another address. I now want to do that again, and find 
that it no longer works. I'm using Sendmail 8.13.1 on 6-CURRENT from 20040905 
(i.e. pretty much FreeBSD 5, but with one crucial fix so it would boot on my 
computer).

I have sendmail_enable="YES" in rc.conf, I have my aliases and virtusertable 
files the way I want them, sendmail's running, and listening on port 25. 
However, one thing has changed since the last time I tried this - I'm now on 
a LAN. The router sends all port 25 stuff to my server, and that works fine. 
But it means that my server has an IP that it can't resolve, though its 
domain name resolves into the correct IP and gets to the server even from on 
the LAN. I've tried adding this local IP to /etc/hosts for kicks. Nothing 
changed.

Every time I try to send a message to any user on the system, from 
virtusertable, aliases, or a real user, I get the error 550 5.7.1 "relaying 
denied", followed by 550 5.1.1 "user unknown". I get a user unknown error 
when I try to mail root. Which is bad. This happens to mail sent from either 
inside or outside the LAN. Mail sent on the server itself is delivered fine. 
I've tried adding my local network's IP range to Sendmail's access file 
allowing relay, but that didn't change anything either. And yes, I did 'make' 
in /etc/mail after making all these changes.

Last time I tried this Sendmail worked "out of the box," so I have no idea how 
anything actually works. Any ideas?

Thanks,

-David