http://mail.python.org/pipermail/mailman-users/2005-July/045647.html
You can use ~mailman/bin/config_list with the -o switch to save the
format of a list in an text (editable) format. You can remove
list-specific items from the resulting text file, and then use
config_list's -i switch to import the configuration information for
another list. (Run 'config_list --help' for more details.)
이렇게 하면 된다고 한다.
해보니 잘 되는 듯.