[Mailman-Users] Problem - User Unknown

[Mr. Sharkey]

Hi, I'm using Mailman v1.0cr2, Mandrake Linux,
and Sendmail 8.9.3. I've created a mailing list,
it shows up with a listinfo and admin page, but
when I try to mail to it, my system returns
'User Unknown'. Any suggestions on where to
start looking to see what's gone amiss?



Thanks,

M.