mx2.e-tiger.net has no CNAME records.
Question and response
Question
dig mx2.e-tiger.net. NS
Answer
The response has no answer records.
Authority
e-tiger.net. 2976 SOA ns1.e-tiger.net. hostmaster\@e-tiger.net. 2025112901 43200 14400 2592000 14400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0