[Mailman-Users] Can not reply to Mailman List

[Lesley Jones]

Hello,
I am trying to implement a list serve for the college I work for to
replace our old, out-of-date list serve.

I have set up Mailman on Redhat 9 with Postfix.  I can create lists and
add members to the list just fine.  I have used many different email
addresses for the list members.  I have used addresses from a different
college, hotmail, and 3 of our internal addresses here at this college. 


The problem is, all but one of these addresses can REPLY back to the
list.  They all receive the mail, but one of my internal addresses of
xx.mydomain.edu can not reply, yet mydomain.edu can.

Does anyone have a suggestion of what might be going on? A setting I
have overlooked in the postfix config file?

Any suggestions would be greatly appreciated.

Thank you,
Lesley Jones