[Mailman-Users] Autentication and problem

[Ana Carolina Alonso]

Hello! I'm a mailman user, I had installed and configured a lot of lists in 
my machine.
I have a problem with one list, when somebody send a mail to the list some 
times some persons (who has subscript to the list) dosn`t receive the mail, 
I don`t undertand why happend, Which is the way to view which mails had 
reveived each person?

Another question: when I go to 
http://mail.python.org/mailman/roster/mailman-users and I want to access to 
some address the password is requerid, who set this option for my lists?

Sorry for my english. Thanks in advance.

Ana