sink.edelkey.net has no MX records.
Question and response
Question
dig sink.edelkey.net. MX
Answer
The response has no answer records.
Authority
edelkey.net. 3600 SOA ns1.edelkey.net. hostmaster.fi.fujitsu.com. 2026022001 1800 900 1209600 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0