Backup Email Forwarders and Filters in Cpanel
From Lunarpages Web Hosting Wiki
Q: In Cpanel, how do I backup my Email Filters and Forwarders?
A: You can backup the forwarders (aliases) you have created and the email filters just in case of a server error or an accidental keystroke. In Cpanel, go to Backup. At the bottom, you will see tables for Aliases and Filters. Click on the domain name or subdomain under the item you wish to backup. This will create a file that you can download to your computer for safekeeping and easy restoration. To restore, just use the restore facility which is to the right.
We highly recommend that you create and keep your own backups, particularly if you have gone to the trouble to create a complicated set of filters or forwarders.