smtp2.mail.ascio.com has no CNAME records.
Question and response
Question
dig smtp2.mail.ascio.com. NS
Answer
The response has no answer records.
Authority
ascio.com. 300 SOA ns1.tucows.com. hostmaster.tucows.com. 1772064000 1800 900 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0