mx4.printhosting.com has no NS records.
NS records for this zone are defined at printhosting.com.
NS records for this zone are defined at printhosting.com.
Question and response
Question
dig mx4.printhosting.com. NS
Answer
The response has no answer records.
Authority
printhosting.com. 1800 SOA ihsaddc02.printhosting.com. dom-admin.efi.com. 5934598 900 600 172800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0