You would first need to either have purchased a hardware Email Security Appliance (ESA) or Virtual Email Security Appliance (vESA). You'll need to reach out to a reseller or Cisco Sales to initiate any purchasing solutions that is applicable for you. Please see the following site for main information:
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...