Use the following steps to setup an email forward.
From the My Account section, under the Domain Tools section click on the MANAGE DOMAINS & EMAILS link as shown below:
From the domain list, click on the domain you would like to modify.
From the email list, click on the email address you would like to modify.
There are 2 options to consider if you would like to setup an email forward. You can either forward the email to User Login or to an email address. See the screenshot below.