At first I had my main domain "main.store" with a MX record mail.main.store. Then I moved a main domain to outside server (Nameservers in "whois" and IP for "main.store" A record were changed). But I still host my app on the Winhost on subdomain "sub.main.store" with Winhost's IP. After these manipulations incoming emails have stopped coming to mail adresses "...@main.store". But outgoing emails work perfectly. Answer: is it possible to use Winhost's MX record when nameservers are changed to third-party server? If no, what can I do still use mail adresses "...@main.store"?