Question and response
Question
dig smtpb1.bt.com. SRV
Answer
The response has no answer records.
Authority
bt.com. 600 SOA EDDNS0.BT.COM. zzdnsr.bt.com. 2006031107 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0