To sign up for Yandex.Mail for Domain:
Register a Yandex account
You must have a Yandex account in order to use Yandex.Mail for Domain. You can connect up to 50 domains per account. Register if you haven't done so yet.
Prepare the domain
Make sure that your domain is ready to work with Yandex.Mail for Domain:
Register the domain with a company that provides such services, if you have not done this yet (Yandex can't register your domain).
Delegate your domain to the servers of the company that is providing DNS hosting.
You can delegate the domain to Yandex servers to automatically connect it to Yandex.Mail for Domain and manage DNS records through the service's interface. However, you must add the domain to Yandex.Mail for Domain before you can delegate it to Yandex servers.
Connect the domain to Yandex.Mail for Domain
Set up the MX record
Configure the MX record on your DNS hosting company's website. To use Yandex.Mail for Domain, you need to create an MX record with the value “mx.yandex.net.”.
If you delegated your domain to Yandex servers, the required MX record will be created automatically.