smtp243.em5service.cz.
Question and response
Question
dig 243.128-255.230.185.89.in-addr.arpa. PTR
Answer
243.128-255.230.185.89.in-addr.arpa. 1800 PTR smtp243.em5service.cz.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0