Store Configuration by Server Based Discovery Fails

When attempting to configure Receiver Stores by entering in address of StoreFront server in Email/Server Based Discovery dialog, the following error appears: "Your account cannot be added using this server address. Make sure you entered it correctly. You may need to enter your email address...

Unable to add gateway URL to the Workspace app. Your account cannot be added using this server addre

Account Adding failure in Citrix Workspace via inputing Gateway FQDN with below error: "Unable to add gateway URL to the Workspace app. Your account cannot be added using this server address. Make sure you entered it correctly. You may need to enter your email address instead."...