ntpzrh8.ntppool.net has no MX records.
Question and response
Question
dig ntpzrh8.ntppool.net. MX
Answer
The response has no answer records.
Authority
ntppool.net. 600 SOA ns1.us.bitnames.com. dnsoper.bitnames.com. 2026022201 600 900 3628800 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0