Email stuck in the Outbox in Microsoft Outlook
If an email seems to be stuck in your Outbox, continue on to the steps below to either clear the stuck message or see if a bad connection to your mail server is stopping the message from being sent.
Clearing a stuck email
To clear stuck email, follow these steps
In Outlook, click the Send/Receive tab, and then click Work Offline.
Note: This stops Outlook from trying to send all email messages.
Select the Outbox. You can now:
Move the message: Move the message to the Drafts folder. You can either drag the message to the Drafts folder or you can right-click the message, select Move, select Other Folder, and then select the Drafts folder from the list.
Note: This enables you to open the large email message, and remove, resize and re-add the attachments before you try to resend the email message again.
Delete the message: Right-click the message and select Delete.
IMPORTANT: If you receive this message "Outlook is transmitting the message" close Outlook and wait for it to exit. You may have to use Task Manager in Windows to make sure that the Outlook.exe process is completed. Restart Outlook again and repeat the previous steps to either move or delete the email message.
Click the Send/Receive tab, and then click Work Offline to de-select it. This restarts your connection.