Allows only specific systems to make admin connections to the firewall. You may have to create several additional rules allowing firewall access depending on your setup. Examples include if you are using encryption or content vectoring. This is the actual lockdown rule. It denies any other connection attempts to the firewall.
Many organizations allow their internal users any service outbound.
The destination Any in this rule includes the firewall. This rule allows the Internet to connect to an internal mailserver. Many companies receive email in this manner. The standard clean up rule. If the session was not accepted, drop the packet and log the session.