We have two mail firewalls (Border Ware ) in the DMZ area, their ip addresses are 192.168.101.3/24 and 192.168.101.5/24

To implement load balancing (mails to be delivered to both of them in equal ) on these mail firewalls, I have been advised to use NAT for these two private ip addresses (192.168.101.3 and 192.168.101.5) to two different (not one) public ip addresses.

Since we have not got two much public ip addresses, my suggestion was to use PAT (not NAT),,,but when I use PAT can a PIX implement load balancing ?