mailx.hoster.ru has one IP number , which also has a corresponding reverse pointer. stg-ksa.com point to the same IP. mkf.ru, kxo.ru, d2d.ru, csb.su, aboo.ru and at least 100 other hosts use this as a mailserver. hoster.ru is a domain controlled by two nameservers at hoster.ru themselves. They are on the same IP network. Incoming mail for hoster.ru is handled by one mailserver at filanco.ru. hoster.ru has one IP number. mailx.hoster.ru is hosted on a server in Russian Federation.