Question and response
Question
dig mx2.emailsrvr.com. NSEC
Answer
The response has no answer records.
Authority
mx2.emailsrvr.com. 300 SOA pdns219.ultradns.com. postmaster.emailsrvr.com. 2016061668 10800 3600 604800 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0