$(HostName)
Contains the host name of the server where the e-mail was created.
$(HostNameFQ)
Contains the fully qualified host name of the server where the e-mail was created.
$(HostIPAddress)
Contains the primary host IP address of the server where the e-mail was created. If the system has IPv4 and IPv6 addresses the first IPv4 address is used.
$(HostIPv4Address)
Contains the primary host IPv4 address of the server where the e-mail was created. If the system does not have an IPv4 interface the value is empty.
$(HostIPv6Address)
Contains the primary host IPv6 address of the server where the e-mail was created. If the system does not have an IPv6 interface the value is empty.