Messages remain in an Exchange Server outbound queue until a non-delivery report is generated when you send e-mail to a remote domain
Problem description
When you send e-mail messages to certain external domains, they may remain in an outbound queue on the Microsoft Exchange Server 2003 or Microsoft Exchange 2000 Server computer until a non-delivery report (NDR) is generated.
Solution Information
Configure the XEXCH50 Registry sub-key or configure the SMTP Connector.