Open up your mailbox under Manage > Mailboxes. Here select the Connection Settings on the left menu.
On the Connection Settings page, click on the Incoming tab, and you'll see the unique identifier address which is your forwarding alias. Copy it to your clipboard and head over to cPanel account.
From the Email section, click on the Forwarders icon.
Click the Add Forwarder button. This will take you to the forwarder setup page.
Create the address you'd like to forward messages from. In this example, it's email@example.com. Next, paste your HelpNinja forwarding address in to the Forward to Email Address field under destination. Click the Add Forwarder button when you're done.