MX record for Subdomain

[Mubi]

Want to add MX record for Subdomain , like master domain is xyz.com subdomain is abc.xyz.com , and its MX record is smtp.abc.xyz.com and mail.abc.xyz.com

i have created Master domain, under zones

then i created A records,NS records,MX records under Resources

then i created Server, Pool and Widip under DNS

but when i do this all for subdomain except adding as master domain,

i can't see the result,