How to block all website except gmail and ymail by layer7

How to block all website except gmail and ymail

You can use layer 7 protocols

For accept rule:
Name: Accept
regexp= ^.+(gmail.com|mail.google.com|yahoo.com|login.yahoo.com|in-mg61.mail.yahoo.com).*$

For deny rule:
Name=Block  regexp=^.+(.).*$

Need two filters rules
1. action=accept and L7=(Accept)
2. action=drop and L7=Block

if u have any trouble to understanding. inbox me :)