Question and response
Question
dig smtp.dockersrc.us. NS
Answer
smtp.dockersrc.us. 5 CNAME mx1.dockersrc.us.
Authority
dockersrc.us. 10793 SOA dns.dockersrc.us. dns-admin.dockersrc.us. 2026010260 10800 3600 1209600 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0