crmail13.infimail.com has no CNAME records.
Question and response
Question
dig crmail13.infimail.com. NS
Answer
The response has no answer records.
Authority
infimail.com. 10800 SOA infimail.com. Postmaster.infimail.com. 637748924 10800 3600 172800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0