Hi Chris, Is this server receiving incoming connections from SMTP servers outside the firewall? If not, then you don't need to worry about this unless your internal network is compromised. Thomas W Shinder www.isaserver.org/shinder <http://www.isaserver.org/shinder> ISA Server and Beyond: http://tinyurl.com/1jq1 Configuring ISA Server: http://tinyurl.com/1llp <http://tinyurl.com/1llp> -----Original Message----- From: Allen, Chris [mailto:CAllen@xxxxxxxxxxxxxxxx] Sent: Friday, September 26, 2003 8:54 AM To: [ExchangeList] Subject: [exchangelist] RE: Relaying question http://www.MSExchange.org/ The problem is, I need to allow relay internally. I have various custom apps that the users need to email a client upon completion of a workorder. They each do over 500 a day and automation is the only way to do this effectively. So, if I shut off the checkbox in question, will the internal IPs still be able to relay? -----Original Message----- From: Thomas W Shinder [mailto:tshinder@xxxxxxxxxxxxxxxxxx] Sent: Friday, September 26, 2003 9:50 AM To: [ExchangeList] Subject: [exchangelist] RE: Relaying question http://www.MSExchange.org/ Hi Chris, Yes. If you don't allow relay, then the server will not relay. You can also do other things like prevent the machine from resolving Internet host names (just for fun). HTH, Tom Thomas W Shinder www.isaserver.org/shinder <http://www.isaserver.org/shinder> ISA Server and Beyond: http://tinyurl.com/1jq1 Configuring ISA Server: http://tinyurl.com/1llp <http://tinyurl.com/1llp>