I have a mail server running windows 2003 sp2 and for some reason it stopped sending email. I have no problems receiving email. The mail just sits in the queue and goes no where. At the moment I have a connector setup in exchange system manager so that mail can be sent through another address until I get our issue fixed. Any ideas of where I can start troubleshooting?

Hi, Which queue did the message hang? Whether any NDR message was received? Please check whether you configure any Smart host under Delivery tab on Default SMTP Virtual Server. If so, please remove it. Thanks Allen

Hi Allen, No smart host configured. Thanks. Renee

see if you can resolve external domain names also see as Allen said if any NDR message was received?