Anonymous remailer: Exim CPanel configuration

I need a CPanel exim configuration to implement a craigslist like anonymous remailer. This means that users on my site will be able to exchange em-ails from their personal em-ail account to an em-ail of the sort . Both the from address and the to address will be rewritten to avoid revealing the true em-ail addresses. This is the basic feature and it's already implemented. I need your help with these additional requirements: 1) Bounce an em-ail that is not from a know user address unless it's to site admin 2) Log every user to user em-ail in a way that can easily be accessible from php 3) Run a simple db query of who sent an em-ail to whom on each user to user em-ail sent 4) Add a custom em-ail header to each user to user em-ail 5) Limit the number of em-ails per sender per day 6) Limit the number of recipients for a user to user em-ails My site is: CENTOS 6.3 x86_64 kvm – server1 WHM 11.36.0 (build 14)