This is a simple notification that your DNS server has satisfied the request of the server on IP address x.x.x.x to transfer the zone. DNS zones by default can be transferred to anyone; on NT4 Server and even better on Win2000, you can disable or limit the zone transfers, since it can be considered as a security measure. To test the zone transfer, open a CMD window, run nslookup, and type:
> server <ip address> (your server''s IP address)
and then
> ls -d mydomain.com (substitute mydomain.com with the name of the domain your DNS Server is authoritative of)