[Mailman-Users] Ddelivery status not sent to Mailman

[Futchko, Rose]

Dear Mailman Users Group,

I know I have a misconfiguration somewhere in my POSTFIX MTA, but am not
sure where and was hoping someone could point me to the right
documentation.

I have some users sending messages to lists of which they are subscribed
to and they successfully deliver, but there are some email users
deliveries that fail and that delivery status is sent back to them (the
sender) rather than the MAILMAN list owner. 

Can someone please advise what I need to do to properly return a
delivery status notification to the MAILMAN List Owner to correct this
problem? Thank you, Rose