mailman list migration, centos to ubuntu

[David Mehler]

Hello,
Has anyone taken one or more mailman mailing lists from a centos box
and successfully set them up on a ubuntu server? I'm trying to do just
that, got apache, postfix, and mailman installed on both servers, have
rsynced over the lists folder, data folder, and aliases and
virtual-mailman files. On the new server whenever i atempt to send a
message to the new list i'm getting an unknown mail transport error.
Any suggestions welcome.
Thanks.
Dave.