See the NAT section for more details.
WAN IPv4 Address: If your CommuniGate Pro Server has several network interfaces, some connecting it to the LAN, and some - to the WAN (Internet), use this setting to specify the IP address the Server OS uses by default when connecting to remote hosts over the Internet:
If your CommuniGate Pro Server is installed on a LAN behind a NAT/Firewall, the NAT/Firewall device should be configured to relay all connections on its communication (POP, SMTP, SIP, XMPP, etc.) ports to the CommuniGate Pro Server LAN address. Use this setting to specify the IP address your NAT/Firewall "relays" to CommuniGate Pro.
For example, if your CommuniGate Pro Server has the 10.0.1.12 IP address on your LAN, and the NAT/Firewall relays all incoming connections coming to the 22.214.171.124 IP address to the 10.0.1.12 address, specify the 126.96.36.199 IP address in this setting:
WAN IPv6 Address: If your CommuniGate Pro Server is connected to the IPv6 network, specify the Server IP address the Server OS uses by default to connect to remote hosts over the IPv6 Internet.