It is very poor practice to use CNAME for things like this. In the example above, mat-sts.his-domain will inherit any records of his-domain: A, AAAA, MX, and wh

It is very poor practice to use CNAME for things like this. In the example above, mat-sts.his-domain will inherit any records of his-domain: A, AAAA, MX, and what not. Don't use CNAME for this.