(The primary task of ISAServer2004 is to isolate unauthorized access requests between internal and external networks. However, many servers in the enterprise need to be released to enable users from the external network to access normally. The release of Exchangeserver is the difficulty and point of ISA release. One, how to allow our employees to access their mailboxes smoothly through the ISA firewall, whether inside or outside the enterprise, is the main content of this course, we will talk about how to publish SMTP and POP3 , as well as the use of publishing OWA and RPC over HTTPS.)