Click on the Block an E-mail link in the Mail Menu area.
Click on the 
button next to the spam filter that you want to delete.
Delete a spam filter when you no longer need it. There is no way to modify a spam filter - if you have made a mistake, simply delete the filter and start again.
To delete a spam filter:
Click on the Block an E-mail link in the Mail Menu area.
Click on the button next to the spam filter that you want to delete.