mxout3.service.a1.net has no MX records.
Question and response
Question
dig mxout3.service.a1.net. MX
Answer
The response has no answer records.
Authority
a1.net. 3600 SOA dns1.a1.net. domainadmin.a1.net. 2026021800 10800 3600 1814400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0