Step 1: Login to your cPanel account.
Step 2: Click on the Email Filters icon on the main screen of your cPanel interface.
Step 3: Click on Manage Filters next to the account for which you wish to add filters.
Step 4: To add a filter, click on Create a new Filter.
Step 5: In the Filter Name field type in a unique name for the filter.
Step 6: From the Rules options you should choose the rules a mail should match in order to be filtered.
Step 7: From the Actions drop-down menu you should choose what action should be performed when a mail matches a rule in the filter.