[Mailman-Users] Subscribers not receiving mail

[Buddy Logan]

Just set up an account.
Entered 4 subscribers in the mass subscriptions form. (All my own addresses for test purposes.)
Received acknowledgment that the account had been set up.
Received acknowledgement that the subscribers had been registered.
Subscribers received "Welcome" messages.
Messages posted to list are received by admin address, and notice of posting is received by the poster.
Subscribers are not receiving postings to the list.

After hours of messing around with settings, I started over with a new account.
This time I did not change any of the default settings.
All responses were the same as above.

I'm very time-urgent on getting this up and running. 
Any ideas?

-- Buddy Logan
buddy at databoysoftware.com