[Exim] Another Mailman question: Child process returned 2

Hi,

I've successfully run Exim 3 with Mailman 2.0 but I'm running into a
snag on setting up Mailman 2.1 under Exim 4.12. I've configured
according to the howto doc. Lists are created fine and notifications of
new lists are delivered to the list admin, and new list subscribers
receive their notifications. However when a list subscriber attempts to
send to the list the mail is bounced with a "local delivery failed" error.

The mainlog shows this entry (the host name is changed):

2003-02-13 23:50:28 18jT7c-0007J5-00 ** test-list@???
R=mailman_router T=mailman_transport: Child process of mailman_transport
transport returned 2 from command: /usr/local/mailman/mail/mailman

I've fiddled with ownerships without success.

I know this is probably a very simple fix and someone knows what I'm not
catching. Help?

Thanks!
Todd