mail distribution list in postfix
I would like to implement mail distribution list in postfix. Current setup of our mail server is using aliases from the file /etc/aliases. The problem with aliases is: If the user is there in more than one alias to which the mail is sent, the same mail repeats for that user. Most users find it annoying.
Can anyone help me in introducing a solution like mail distribution list in postfix. So that postfix itself will take care of the duplicate mails.
Thanks in advance.