a.mx.staeher.net has no MX records.
Question and response
Question
dig a.mx.staeher.net. MX
Answer
The response has no answer records.
Authority
mx.staeher.net. 3600 SOA a.dns.staeher.net. dns-admin.staeher.net. 2025020100 10800 3600 1814400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0