smtp01.mts.am has no MX records.
Question and response
Question
dig smtp01.mts.am. MX
Answer
The response has no answer records.
Authority
mts.am. 600 SOA ns2.viva.am. ns.viva.am. 2026012101 3600 600 1296000 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0