DNS records for smartsites
The IP address for all realsmart smartsites is 220.127.116.11
smartsites typically require only two DNS records, one for the domain apex (or root) - the bit after the www - and one record for the www subdomain.
If you want to have your smartsite hosted at a specific subdomain rather than your domain apex you will need to add a DNS record for that subdomain instead.
It is necessary to delete any existing A records for your domain apex and www. subdomain.