mx0 ~ # host -t mx gb2bel.ru 8.8.8.8
gb2bel.ru mail is handled by 10 mx0.gb2bel.ru.
mx0 ~ # host -t A mx0.gb2bel.ru 8.8.8.8
mx0.gb2bel.ru has address 77.247.238.134
mx0 ~ # host -t TXT _dmarc.gb2bel.ru 8.8.8.8
_dmarc.gb2bel.ru descriptive text "v=DMARC1; p=none; sp=none; rua=mailto:postmaster@gb2bel.ru"
mx0 ~ # host -t TXT _adsp._domainkey.gb2bel.ru 8.8.8.8
_adsp._domainkey.gb2bel.ru descriptive text "dkim=all"
mx0 ~ # host -t TXT mail._domainkey.gb2bel.ru 8.8.8.8
mail._domainkey.gb2bel.ru descriptive text "v=DKIM1;k=rsa;t=s;p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCzZgqURuPhiSU70+B1luSwsQYdV1fde+tfAHv7Ncmiy7P3/QjNV75OEAGknQF+L/OIw1OOGkCrmHmbslvP99RZQa0usTRo74Mi6wfNCtqg6pn3jCXWDwfU2uvdLEBR3XkoC82LdIOCBF9ROVPxpKjV55op1/Uxt/t2qjKVZoCr/QIDAQAB"