_spf.mail.ptl.ru has no MX records.
Question and response
Question
dig _spf.mail.ptl.ru. MX
Answer
The response has no answer records.
Authority
mail.ptl.ru. 3600 SOA ns.quantum.ru. admin.quantum.ru. 2024021904 0 10800 3600 604800
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0