Thanks everyone, for the help w/ this. This ended up being the fix. The 
goal was to have my email address be "dorfman@est.org" where 
"paige.est.org" was the mail host. For those who care, I did what it said 
below, plus I added just "est.org" to the file.

Thanks again,

-Capt Avram Dorfman
Chief, Network Operations
email: dorfman@pentagon.mil
(last resort email: avram@pobox.com)

:%s/\(do|-<\)/\1\1/g
:1,$d

On Sat, 10 Jan 1998, Mark Andres wrote:

> Hi,
> 
> Here is how I do it.
> 
> In the /etc/sendmail.cf file, locate the line that says:
> 
>   Cwlocalhost
> 
> Below it, add the following line:
> 
>   Fw-o /etc/sendmail.cw
> 
> Now, create a file called /etc/sendmail.cw  In that file, add the fully
> qualified host name.  In your case, I believe the following should do it.
> 
>   paige.est.org
> 
> You will need to kill and restart sendmail, but that should do it. Then,
> if you MX mail for any other hosts you yours, just add another line to the
> /etc/sendmail.cw file.
> 
> Mark
> 
> On Fri, 9 Jan 1998, Capt. Avram Dorfman wrote:
> 
> > Ok, I think I need to rephrase my question... I appreciate all the 
> > responses, but it wasn't that I needed another sendmail.cf - I have a 
> > fresh one.
> > 
> > I just can't remember what I need to do so I stop getting the message:
> > 
> > 	"config error: mail loops back to me (possible MX problem?)"  
> > 
> > I had this once before, either when I first set up sendmail, or when I
> > first configured it to use my domain name instead of my hostname, as my
> > email address. Like I said, I haven't changed my DNS records.  All I've 
> > done is upgraded to 1.3, and accidentally replaced my sendmail.cf (ok, 
> > actually my entire /etc) with the distribution.
> > 
> > I've got masquerading set so that my outgoing mail looks like it comes
> > from "est.org", but there's something I need to do so that paige.est.org
> > doesn't try to relay received mail to est.org, since paige is supposed to 
> > *be* est.org as mail goes. 
> > 
> > And yes, this is my work email address that I'm writing from...
> > 
> > -Capt Avram Dorfman
> > Chief, Network Operations
> > email: dorfman@pentagon.mil
> > (last resort email: avram@pobox.com)
> 
>    Mark Andres               E-mail: mark@giganet.net
>           Running NetBSD, 100% Microsoft Free!
>    Me & NetBSD: http://www2.giganet.net/~mark/NetBSD/
>