The LocalDomain property is used to set the domain name for
the local host. The local domain name is used when the name assigned
to HostName property does not specify a domain (in other
words, does not have a dot in the name). In that case, the value of
the LocalDomain property is appended to the hostname.
If a domain name has been specified for the local system, the
LocalDomain property is set to that value by default.