How do I set up mail forwarding from my SMTP server?

Question

linux

Good morning.
There is a server on which there is postfix + dovecot.
Now this bundle sends letters from @subdomain.example.com, and receives letters to the same mailboxes (virtual_alias_maps is registered in the postfix config: forward everything from *@subdomain.example.com to one mailbox).
I would like to set it all up so that:
1. emails from/to @subdomain.example.com work the way they do now;
2. letters from/to example.com worked through Yandex traffic rules.
How can this be done?

Answer 1

The correct answer is to set up two mx records for the domain and subdomain, and two A records for the domain and subdomain.

A	@		192.0.2.0
A	subdomain	192.0.2.0
MX	@		mx.yandex.net
MX	subdomain	subdomain.example.com

Answer 2

For example.com, set up the Yandex traffic rules MX server, add an account for Yandex on clients.