[Mailman-Users] Subscribe not functioning

[rdembski at sbcglobal.net]

External subscribing is not working thru either the
web interface or the list-subscribe at hostname.org
method.  There is no confirmation message being
sent...  I can subscribe locally thru email, can
manually add addresses thru the admin interface, and
can even send/receive list mail from any
already-subscribed address with no problem.

I've looked thru the FAQ, the FAQ wizard, searched
this lists' archives the best I can, and still cannot
find anything similar enough to suggest a problem/fix.

I'm using Mailman 2.1.6rc4, Exim 3 on Debian GNU/Linux
3.

Any help/suggestions would be greatly appreciated. 
Thanks.