[Mailman-Users] DNS/Sendmail issue upon install

[colleen at sdo.net]

Greetings everyone!

I am running mailman-2.0 on Redhat Linux 7.3.

I have successfully installed mailman onto my server. I have sucessfully
added an admin and a few users through the web interface to a test list.
Unfortunately, when I try to send an email on the list, I get this:

The original message was received at Thu, 29 May 2003 14:39:39 -0700
from apache at localhost

   ----- The following addresses had permanent fatal errors -----
<test2 at sdo.net>
    (reason: 550 5.1.1 User unknown)

   ----- Transcript of session follows -----
550 5.1.1 <test2 at sdo.net>... User unknown

Mailman is sending mail out to users who subscribe, but the list itself is
not operational. Is there a particular default setting I should look at?

Thanks!
Colleen