- You are using Microsoft Office Outlook 2003 Service Pack 1 (SP1).
- You are using either a Post Office Protocol version 3 (POP3) account or an Internet Message Access Protocol (IMAP) account.
- The e-mail message was sent to one or more people who are not in your domain.
- Outlook 2003 is configured to receive an NDR message for all recipients.
Currently, there is no resolution for this issue. Because the e-mail message was not delivered to any recipients, the fact that you have an empty From field in an-email message that is in your Sent Items folder would be known only by you.