How to correctly register mx for a subdomain?

Question

Mail server

Hello.
Tell me, please, how to create "mail for a domain" on a subdomain - specifically, it does not find MX records. As soon as I did not try - a screenshot is attached.

Thank you.

Answer 1

If you have the main domain.com domain and the sub.domain.com subdomain, then for [email protected] mail, you must register the MX record for sub in the dns control panel.
sub.domain.com, www.sub seems redundant.
If you just registered, it may take time for Yandex to see the changes.
The same subdomain must be added to Yandex (I have not tried to add subdomains there before) - "sub.domain.com".