E-Mail Forwarders allow you to forward mail from one account to another account. This account can be another account that is on your domain or it can be an offsite e-mail account.
Note concerning e-mail forwarders
There are a couple of things to consider before creating a forwarders. If the account you are forwarding from is already a POP Account on your domain, then mail will get delivered to both places. For example if your domain name was domain.com and you wanted to forward mail from firstname.lastname@example.org to email@example.com and the POP Account firstname.lastname@example.org already existed then mail would be delivered to both places. The email@example.com must be setup or else the mail will get sent to the default box.
Generally, setting up e-mail forwarders to forward e-mail off of the server is not recommended. Setting up e-mail forwarders to forward mail within your own domain is not a problem. Information concerning why forwarding e-mail off of the server is available at this guide
If the POP account firstname.lastname@example.org does NOT exist, then any mail addressed to email@example.com will be sent to firstname.lastname@example.org. The address the mail is forwarding from, in this case email@example.com does not have to be set up as a POP account. The system will know to send any mail addressed to forwarder account to the forwardee account.
When you click ont he E-Mail Forwarders link you should see a page similiar to the one below, assuming you have not set up any E-Mail Forwarders.
To begin, you will need to click the Add a New E-mail Forwarder link.
In the first textbox you will need to enter the account name of the address you want to act as the forwarder. Keep in mind that this account does not have to be a created POP Account. It should only be a created POP account if you want mail to be delivered at both places. In the dropdown list you can select the domain or subdomain you want the forwarder to act upon, commonly this is just the main domain name. In the third and last textbox, fill out the complete e-mail address you want the e-mail messages forwarded too, the forwardee. If the e-mail address is an address on your domain, you will see need to enter the complete e-mail address.
In my example below, I am setting up the address firstname.lastname@example.org to be forwarded to email@example.com. I do not have the POP account firstname.lastname@example.org setup, so any time someone sends a message to email@example.com the message will get forwarded to firstname.lastname@example.org.
After you click Add Forward you will see a message confirming that the forwarder has been setup and how it will act. If you go back to the E-Mail Forwarders page, you will now see the forwarder that you just setup.
You will also notice a Delete button beside the forwarder. You can use this button to delete the forwarder later.
You can setup as many forwarders on an account as you want. Each time an e-mail message is sent to the forwarder account it will get sent to each forwardee address that is setup on the forwarder account.