How can I configure our ASA 5510 ver. 7.2(2) to prevent all smtp traffic except from our email servers (2 of them). We want to make sure that a possible virus would not be able to spam out email and then have our IP Address blacklisted. All incoming email is directed to our Barracuda Spam filter first and then sent to our email servers. The spam filter is behind the firewall. All outgoing email will also be directed through the Barracuda in the future. Thanks.