How to send mail through "mail for domain" and through the hoster's server?

Question

Mail server

There is a hosting and a domain in the ru zone.
The task is to receive / send letters through the box X and Y (via the Yandex server). And through mailbox Z to receive / send letters (not through Yandex mail servers (the "mail for domain" service), but through the hosting server).
How much do I know if this is possible? How to implement this so that both X and Y and Z work?
I connected X and Y. Works through "mail for domain". Just usually letters through the Yandex server, or through the hosting server. And I need both options to work, but not for the same boxes, but for different boxes X, Y, Z.

Answer 1

Do not suffer and use Pdd.yandex.ru

Answer 2

I say, I use Pdd.yandex.ru and I also want to use mail through the server from the host. How to do it at the same time? You apparently do not carefully read my question and did not understand the problem that I want to solve. Are there any more gurus?