mxout3.service.a1.net has no CNAME records.
Question and response
Question
dig mxout3.service.a1.net. NS
Answer
The response has no answer records.
Authority
a1.net. 1799 SOA dns1.a1.net. domainadmin.a1.net. 2026022504 10800 3600 1814400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0