[Mailman-Users] transports not working

[Rantanen, TC1]

I am not able to build the lists via  email but I can build it with a the
add_member command.
Also the pipermail/test has an error when it comes up. Does mailman use
pipermail?

I copied the config section from the howto into the exim.conf file. 
Also copied the info from creating a list into /etc/aliases then did a
newaliases.

Anybody have an idea where to look for the error below?

delivering message 16uz3P-0000IV-00
LOG: 0 MAIN PANIC DIE
  Neither the system_aliases director nor the address_pipe transport set a 
uid for local delivery of |/var/mailman/mail/wrapper post test

Ed Rantanen