Email forwarders can be deleted, so long as this is no longer needed. You can do it any time via your cPanel. Before you delete the email forwarder, please backup the emails to save possible important emails.
Here are the steps on how to delete email forwarder via cPanel:
Step 1. Log in to the cPanel using this link format: http://yourdomain.com/cpanel/
Replace yourdomain.com with the Main Domain Name connected to your hosting.
Step 2. Click Forwarders on the Email panel.
Step 3. Under Email Account Forwarders, locate the email forwarder you’d like to delete.
Step 4. Under Actions, click Delete.
Step 5. A prompt will come up, click Delete Forwarder.
A prompt will come up saying the deletion is successful.