mail.citynet.works has no MX records.
Question and response
Question
dig mail.citynet.works. MX
Answer
The response has no answer records.
Authority
citynet.works. 7200 SOA ns1.chv.ua. admin.net.cv.ua. 2026030300 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0