If you're using a self-hosted email address (i.e. you're not using an email provider like Gmail to manage your mail) you can set up your auto-forwarding directly with your host or DNS provider.

The setup process varies depending on your host's platform, so we've collected links below to the setup instructions for some of the major ones. The idea is generally the same in that you take your forwarding address that you're given when you create your Groove mailbox and you add that as a forwarder with your host.