Why are the email forwarding (or URL forwarding) services are not working after switching to custom DNS?
You must use our DNS servers in order to use email forwarding or URL forwarding. If you are using custom DNS, email forwarding and URL forwarding through us will not be available.
To change to our DNS servers, set up email forwarding, and set up URL forwarding, please follow the instructions in the below articles, respectively:
"How to Change Domain Nameservers (DNS)"
"How to Set Up Email Forwarding"
"Forward, Redirect or Point Your Domain/Sub-domain (Change Host Records)"