E-Mail Stuck in Outbox
Outlook Versions: 2003 and 2007
http://support.microsoft.com/?id=291613
How to send e-mail messages that remain in your Outbox in Outlook
CAUSE
This behavior occurs if you are working offline and one of the following situations is true:
• You addressed the item to someone in your local Personal Address Book (PAB).
-or-
• You use a Microsoft Exchange Service and addressed the item to someone in your synchronized
Global Address List or your synchronized Outlook Address Book Contacts.
MORE INFORMATION
If you are working offline, Outlook cannot send the item because it does not have access to the e-mail server.
Because the addressee is available in one of your local address lists, Outlook validates the address. However,
Outlook does not provide an indication that the item remains unsent until you quit Outlook.
Outlook sends the messages the next time that you make a connection to your e-mail server by either
working online or making a remote e-mail connection.
To make a remote e-mail connection while you are working offline,
click Send/Receive on the Tools menu,
click Work With Headers, and then
click Download Headers.
File->Work Offline.
Completely close and then re-open Outlook.
Delete the message.
File->un-check Work Offline.
Close and restart outlook.
http://www.howto-outlook.com/faq/messagestuckinoutbox.htm
Office 2000 - Old Outlook
You Opened the Message from Your Outbox
After you send a message, Outlook moves it into your Outbox. When Outlook establishes a connection to your mail server,
it attempts a delivery and a copy of the sent message appears in your Outbox.
If you open and close a message while it is still in your Outbox, you change the status of the message and it is not sent.
The message title will no longer appear in italic formatting in the Outbox Messages view.
To return the message to Send status, open the message, and click Send on the message toolbar.
The message title should become italicized in the Outbox Messages view.
During the next connection with the mail server Outlook should deliver the message.