dns01.bekknet.ad.jp has no MX records.
Question and response
Question
dig dns01.bekknet.ad.jp. MX
Answer
The response has no answer records.
Authority
bekknet.ad.jp. 2560 SOA dns01.bekknet.ad.jp. hostmaster.bekknet.ad.jp. 1771915434 16384 2048 1048576 2560
Additional
The response has no additional records.