The mailing list for listmasters using Sympa

[address@concealed]

Hy:
I have just installed the sympa on a Mandrake 8.2 and after founding serious 
troubles with differents paths, I finally made it work it out.

I can create lists, and users, sympa even send welcomes messages to new 
users, 

but...

when any user try to send a message to a list, example (mylist), sympa only 
sends a message to a supposed user name mylist.

like address@concealed

Lets say that picks up the list name and send a message to that name.

I read all FAQ, I read manual, I read this list and I do not know why it 
happens

postfix sends messages perfectly because my mail works fine.
As I said before, sympa systems email messages works fine, and are received 
for clients well.
But ordynary messages sent from clients goes to the name of the list 
@mydomain.com

I have installed linux mandrake in two servers and both do exactly the same.

Any help please???

Thanks