Hi, Welcome to JustAnswer. This is Mahbub Shahin can assist you.
Please go to open out box
Look at the draft folder.
You will find your stuck email there.
Delete the mail.
Any more question please let me know.
In most cases, you can delete the stuck message if you set Outlook offline using the File, Offline menu. Wait about five minutes or so for the mail spooler process to shut down or close Outlook and reopen. Go to the Outbox and delete the message then put Outlook back online using the File, Offline menu.
In Outlook 2010, Work Offline is on the Send & Receive ribbon. The screenshot shows the default setting of On. When Outlook is Offline, the button is highlighted in orange.
If your version of Outlook doesn’t include a Work Offline command, disconnect from the Internet or disable the network card in the Control Panel, Network.
This is one time when patience is a definite virtue – make sure you give Outlook time to stop processing the message before trying to delete it. A very large message may require longer than 5 minutes to stop processing.