128.guest-wlan.nblnet.com has no MX records.
Question and response
Question
dig 128.guest-wlan.nblnet.com. MX
Answer
The response has no answer records.
Authority
nblnet.com. 1800 SOA ns1.cygate.fi. hostmaster.nebula.fi. 2017061177 1038951 600 2419200 3600
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0