The "xyz.homeserver.com" domain names are only available under Windows Home Server 2011. The "Essentials" line of servers all use a "xyz.remotewebaccess.com" domain name instead. Therefore, you'll need to run the Anywhere
Access set up wizard (from your Essentials server's Dashboard) and set up a new "xyz.remotewebaccess.com" domain name instead.
The "xyz" domain prefix (subdomain) can be the same as your old one was as long as it's not already taken. The Anywhere Access / Remote Web Access set up wizard will walk you through all of that. Just be sure to choose the "I want to
set up a new domain name" option in the set up wizard in order to create a new Microsoft personalized domain name for your Essentials server (where you'll be prompted to sign in to your Microsoft account).