nsb.tld.md has no MX records.
Question and response
Question
dig nsb.tld.md. MX
Answer
The response has no answer records.
Authority
tld.md. 3600 SOA ns.tld.md. master.tld.md. 2026021117 21600 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0