relay5.TTK.RU has no MX records.
Question and response
Question
dig relay5.TTK.RU. MX
Answer
The response has no answer records.
Authority
TTK.RU. 3600 SOA dns-prim.transtk.RU. nsmaster.transtk.RU. 2026021601 10800 900 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0