Open Source Anti Spam Gateway Open Source AV / SPAM Corporate Gateway?

Open source AV / SPAM corporate gateway? - open source anti spam gateway

I'm an experienced Linux administrator of Windows, but I wanted to know if someone has a system acceptable to success including:
I want an anti-virus open source / SPAM business gateway / proxy for the first cleaning system tap and move mail to an Exchange server. Many of these things, I know, but I really need something that is very similar to using our current SonicWALL Email Security and LDAP to query Active Directory users and enable everyone access to the user via the web interface and e unjunk to submit senders to whitelists, etc. almost certain that this work should be and was part of the various computer programs. I tested with Postfix / SpamAssassin / Clam SMTP / AV, etc., and that's the easy part ... The LDAP search for a quality system, each user has their own spam settings control is very simple ... difficult.
Any help would be very grateful. Let me reiterate that need the most important information is the LDAP / simple user interface control via a web interface, are preferred.