I think the link i gave in above post should be clear enough:
##
# Whitelist
#############
  IP Whitelisting format: 
    INSERT INTO whitelist (_whitelist,_description) \
      VALUES ('127.%.%.%','# localhost');
    INSERT INTO whitelist (_whitelist,_description) \
      VALUES ('192.168.2.10','# lan server');
  Sender Whitelisting format:
    INSERT INTO whitelist_sender (_whitelist,_description) \
      VALUES ('camis@mweb.co.za','# whitelist single address');
    INSERT INTO whitelist_sender (_whitelist,_description) \
      VALUES ('@mweb.co.za','# whitelist entire domain');
    Please note that address whitelist will be matched only against
    the  sender address. For recipient  whitelisting,  please refer
    to the opt-in/opt-out section below.
  DNS name whitelisting
    INSERT INTO whitelist_dnsname (_whitelist,_description) \
      VALUES ('%.mweb.co.za','# whitelist *.mweb.co.za');
    INSERT INTO whitelist_dnsname (_whitelist,_description) \
      VALUES ('%.mail.mud.yahoo.com','# whitelist all yahoo mud mailservers');
    INSERT INTO whitelist_dnsname (_whitelist,_description) \
      VALUES ('n10.bulk.dcn.yahoo.com','# whitelist only this mailserver');
  DNS name whitelisting works as follows:
    [logwall01][/]# host web32804.mail.mud.yahoo.com
      web32804.mail.mud.yahoo.com has address 68.142.206.34
    [logwall01][/]# host 68.142.206.34
      34.206.142.68.in-addr.arpa domain name pointer web32804.mail.mud.yahoo.com.
    The forward and reverse DNS *must* match otherwise it will not work.
    If forward and reverse dns match, then the whitelisting can work.