email.vbulletin.net has no NS records.
NS records for this zone are defined at vbulletin.net.
NS records for this zone are defined at vbulletin.net.
Question and response
Question
dig u2721515.wl016.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl016.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2399164964 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0