Hello, Exchange 2003 sp 2 on an Windows 2003 Standard SP 2 box. No modifications to server recently. We receive our e-mail through MS Forefront for spam and anti-virus. Suddenly (last night), we started getting deferrals. External e-mails are not being delivered. Front Fore defferal will show: timed out while sending end of data The firewall - which only allows incoming smtp from the Forefront servers, will show that a connection is established, yet closes with a TCP RST. All outgoing e-mail is good. E-mail within the Exchange organization is good. I have been able to telnet and deliver e-mail. I restarted SMTP services. I have rebooted the server. I rebooted the firewall. I was able to send a few e-mails from another one account, but not another. Checking the ESM message tracking the only e-mails currently are those that I sent (not the many items in the Fore Front que (although they are coming across the firewall). Hard drives have space to spare. Nothing very obvious. Any suggestions would be appreciated.

Could you please check your MX record once? Please restartt the Forefront Spam services. also browse below site and click on CheckDNS.net Quick Check Utility http://www.checkdns.net/quickcheck.aspx enter your domain name and click on Check. Vinod |CCNA|MCSE 2003 +Messaging|MCTS|ITIL V3|

So the inbound mail flow looks like below: Internet--->Exchange (Forefront) Check info: 1. So, we cant receive any inbound mails from Internet, right? You have tried to send test mails to internal recipients on the Internet, right? Is there any NDR on the senders mailbox? 2. Does the issue happen permanently to the outbound mails from all external domains? 3. Quote: I was able to send a few e-mails from another one account, but not another What do you mean? Do you mean that outbound mail is ok? 4. Please use the methods in this article to troubleshoot the issue