qmail bounces mutt but accepts Eudora?

[John P. Verel]

Greeting from snowy Fairfield County. :|

I belong to a mailing list hosted by coollist.com.  They apparently run
qmail.  If I post using Eudora, it goes through just fine.  If I post
with mutt, I get bounced.  When bounced, the message I get from
qmail-send is that I'm not a member of the list.  I'll be glad to send
all the headers, etc, on request but will spare the bandwidth for the
rest of the world.
-- 
John P. Verel
Norwalk, CT