mxout2.a1.group has no MX records.
Question and response
Question
dig mxout2.a1.group. MX
Answer
The response has no answer records.
Authority
a1.group. 3600 SOA dns3.a1.net. domainadmin.a1.net. 2026020500 10800 3600 1814400 3600
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0