posta.ttidc.com.tr has no MX records.
Question and response
Question
dig posta.ttidc.com.tr. MX
Answer
The response has no answer records.
Authority
ttidc.com.tr. 21600 SOA ns1.ttidc.com.tr. dnsadmin.ttidc.com.tr. 2020101001 21600 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0