mailin-01.mx.sonic.net has no MX records.
Question and response
Question
dig mailin-01.mx.sonic.net. MX
Answer
The response has no answer records.
Authority
mx.sonic.net. 300 SOA ns1.sonic.net. hostmaster.sonic.net. 2025102701 3600 900 1209600 28800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0