defense SPAM for mailserver Postfix.Build webmail ???

From: Mr Minh (
Date: 12/13/02

From: (Mr Minh)
Date: 13 Dec 2002 14:50:01 -0800

I setting up successful a Mail server uses Postfix 's MTA
And now, I 'm trouble with 2 problem:
- defense for Mail server such as :
   ban a mail address on Server ,defense for SPAM from out
- Create Web mail for user can change password ,username and
check mail on Web .It's help Admin not busy with create account for new
employeer in Company.

Help me,