STEP 1 : Login to Direct Admin ( Guide here )
STEP 2 : Navigate to Email Manager -> Fowarders. Click on Fowarders
STEP 3 : Click on Create E-Mail Fowarder ( Top Right Corner )
STEP 4 : Enter your fowarder name ( Email address ) and your destination ( Email Address you wish to foward mails too ). Click on Create after
If succesful, you will be redirected to a page with a list of fowarders. You will be able to see the fowarder you have set up like below