Cpanel not allowing mail forwarding

I am trying to forward mail received at my domain to yahoo and gmail accounts. But when I try to add a forwarder in cPanel or Roundcube, it shows message: The system could not add the forwarder: Forwarding to yahoo.com is not allowed. This happens for both yahoo and gmail target email addresses. I am using Roundcube 1.6.0 and cPanel 110.0.9 alt="Untitled.png">83733