An email forwarder allows you to forward on all of your email to a different email account. The email will still remain in the original mailbox, but a copy will also be sent to whatever email address you would like it forwarded to. You can setup many email forwarders for the same email if you like.
To set this up firstly login to your webmail, to do this goto your website address and add /webmail to the end, for example: https://www.yourdomainname/webmail
Once you have logged in in the top right corner click on "Webmail Home"
Then scroll down to the Forwarders option and click
On the next page click the "Add Forwarder" button
On the next screen type in the full email address where you want your email forwarded to and then click the "Add Forwarder" button
Here is a short video showing you all the above steps