Hello all, I have a weird one here. I have two SMTP Gateway boxes for our organization. One is Win 2003 Server with IIS and the other is Win 2000 Server with IIS. Neither of these servers have Exchange installed, but they do act as Smart Hosts for our Exchange 2003 environment. I have just found out that when someone (externally) attempts to telnet to our SMTP hosts (206.195.131.20 and 206.195.131.69) the following appears: 220 *******************************************************************0**** 0*2******************2******200********0***0*00 If I attempt to type 'EHLO' or 'HELO' I receive the following: 500 5.3.3 Unrecognized command If I attempt to telnet to these servers from an internal PC, using the internal IP address, I get the standard: 220 mail1.globalknowledge.com Microsoft ESMTP MAIL Service, Version: 6.0.3790.21 1 ready at Thu, 28 Jul 2005 11:53:55 -0400 When typing 'HELO' or 'EHLO' I get the normal reply: helo 250 mail1.globalknowledge.com Hello [172.16.5.181] Mail is flowing as it should into our organization, but I am unable to successfully force a Telnet Session to our servers from an external computer. In the past, our servers have responded to telnet requests as if internal, but now they respond with '220 *************' etc. What could be causing this since I have not made any changes to the IIS SMTP config? Any help is greatly appreciated. Chris