mail.sevdesk.com has no NS records.
NS records for this zone are defined at sevdesk.com.
NS records for this zone are defined at sevdesk.com.
Question and response
Question
dig u2848336.wl087.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl087.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2397947545 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0