[Mailman-Users] Fake Email

[Hien HUYNH HUU]

Dear all,
   I recognize that mailman can accept a fake sender . Example, I have a maillist with only an email account (xyz at abc.com) can send messages to all emails in the list. But , if someone can send a fake "From address" is xyz at abc.com, mailman will delivery messages to the list . This is a security problem. Can we prevent this from happening  ? 
  Best regards,
  Huu Hien