Mail site block by IPTABLES

#!/bin/bash
iptables -I OUTPUT -p all --destination mail.rediff.com -j DROP
iptables -I OUTPUT -p all --destination rediffmail.com -j DROP
iptables -I OUTPUT -p all --destination mail.google.com -j DROP
iptables -I OUTPUT -p all --destination gmail.com -j DROP
iptables -I OUTPUT -p all --destination mail.yahoo.com -j DROP
iptables -I OUTPUT -p all --destination yahoo.mail.com -j DROP
iptables -I OUTPUT -p all --destination yahoomail.com -j DROP
iptables -I OUTPUT -p all --destination yahoo.mail.com -j DROP
iptables -I OUTPUT -p all --destination mail.com -j DROP
iptables -I OUTPUT -p all --destination login.live.com -j DROP
iptables -I OUTPUT -p all --destination mail.live.com -j DROP
iptables -I OUTPUT -p all --destination meebo.com -j DROP