I have a new installation of SBS 2008 Premium and Exchange 2007 is generating "451 4.7.0 Timeout waiting for client input" errors on about 1/3 of the incoming messages. The trial period for the Forefront Security package has ended and the product has been removed. Its too expensive for my non-profit client.I raised the ConnectionInactivityTimeout from 1 minute to 2 minutes which had no effect. I set PipeliningEnabled to False which had no effect. I have monitored the traffic with Wireshark and I don't see any data from the remote client.I have searched both Microsoft and the Internet at large without finding a resolution.My configuration is as close as I can get to an exact copy of Technet article 239200, "Scenario 2: Installing the Primary and Second Servers in Hyper-V Virtual Machines on a single Physical Computer". The physical computer is a Dell T310 with 8GB of memory. SBS 2008 with Exchange 2007 is one of the virtual computers.The physical network is DSL with an Actiontec modem/router configured with a block of 8 static IPs. The router provides both NAT and bridging of the static IPs simultaneously. The SBS2008 server is assigned both a public IP and a private IP, the default gateway is the public IP assigned to the router.This is my first Exchange 2007 installation. My other clients running Exchange are all using SBS 2003 with Exchange 2003, a smarthost and the POP3 connector. I have experience running Imail so I have a reasonable knowledge of SMTP protocol.I need to resolve this problem as quickly as possible. If more information is needed or if this isn't the best place for this question, please let me know.Regards,Brad

Is there a firewall? I'm suspicious that you have a firewall that's interfering with the SMTP traffic.-- Ed Crowley MVP"There are seldom good technological solutions to behavioral problems.". "Brad Morgan" wrote in message news:b17cd726-e33f-4264-81a4-071f84aac6c8...I have a new installation of SBS 2008 Premium and Exchange 2007 is generating "451 4.7.0 Timeout waiting for client input" errors on about 1/3 of the incoming messages. The trial period for the Forefront Security package has ended and the product has been removed. Its too expensive for my non-profit client.I raised the ConnectionInactivityTimeout from 1 minute to 2 minutes which had no effect. I set PipeliningEnabled to False which had no effect. I have monitored the traffic with Wireshark and I don't see any data from the remote client.I have searched both Microsoft and the Internet at large without finding a resolution.My configuration is as close as I can get to an exact copy of Technet article 239200, "Scenario 2: Installing the Primary and Second Servers in Hyper-V Virtual Machines on a single Physical Computer". The physical computer is a Dell T310 with 8GB of memory. SBS 2008 with Exchange 2007 is one of the virtual computers.The physical network is DSL with an Actiontec modem/router configured with a block of 8 static IPs. The router provides both NAT and bridging of the static IPs simultaneously. The SBS2008 server is assigned both a public IP and a private IP, the default gateway is the public IP assigned to the router.This is my first Exchange 2007 installation. My other clients running Exchange are all using SBS 2003 with Exchange 2003, a smarthost and the POP3 connector. I have experience running Imail so I have a reasonable knowledge of SMTP protocol.I need to resolve this problem as quickly as possible. If more information is needed or if this isn't the best place for this question, please let me know.Regards,Brad Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Is there a firewall? I'm suspicious that you have a firewall that's interfering with the SMTP traffic. Ed Crowley MVP "There are seldom good technological solutions to behavioral problems." There is not (unfortunately) a firewall. The Actiontec PK5000 DSL modem/router/wireless uses PPPoE to establish the DSL connection and then uses what they call "unnumbered mode" to pass the public IPs through to the LAN. The Actiontec PK5000 also provides NAT. Because some of the client desktop computers use Wireless, it isn't straight forward to put a firewall between the Actiontec and the internal LAN, although I'd love to do that.When I first installed the server, nothing was happening on port 25 so I had to contact the ISP (Qwest) to unblock 25 which they have done.Regards,Brad

Hi Brad, We could see it's a time-out issue. It can be caused by a network problem. You could telnet your server from external and see if it has the same issue. By the way, is the mx record point to your server directly?

How is it not surprising Microsoft told you that your timeout issue is caused by timeouts. No Technet link Elvis Wei? Tsk tsk... The solution is to replace that P.O.S. Actiontec DSL modem with something along the lines of the Motorola 3347. I have two clients with the Actiontec PK5000 and for some reason it screws with SMTP almost entirely from mail that originates from godaddy's SMTP servers. Replaced it with the Motorola 3347 at one of my clients and timeouts disappeared 100% without a single change in any other config.

How is it not surprising Microsoft told you that your timeout issue is caused by timeouts. No Technet link Elvis Wei? Tsk tsk... The solution is to replace that P.O.S. Actiontec DSL modem with something along the lines of the Motorola 3347. I have two clients with the Actiontec PK5000 and for some reason it screws with SMTP almost entirely from mail that originates from godaddy's SMTP servers. Replaced it with the Motorola 3347 at one of my clients and timeouts disappeared 100% without a single change in any other config. I found that the PK5000 was also messing with the mail flow. I replaced it with an Actiontec GT701 and Mail flow returned to normal instantly. Do not use the PK5000 with an Exchange server.