How do I edit or delete a filter once I have created it?

1. Open Gmail.
2. At the top right, click Settings
3. Click Settings.
4. Click Filters and Blocked Addresses.
5. Find the filter you'd like to change.
6. Click edit or delete to remove the filter. If you’re editing the filter, click Continue when you’re done editing.
7. Click Update filter.

You can create as many filters as you like, but only 20 filters can forward to other addresses.