Sometimes messages may be stuck in the Outbox when you use Windows Mail. You cannot send or delete these messages. Every time that you close Windows Mail, you are prompted that there are unsent messages in your Outbox.
To remove stuck messages in your mailbox folders, install the KB941090 Update. After you apply the update, you will be able to delete the messages that are stuck.
Select either the Windows Vsta 32-bit version or Windows 64-bit version. (To see what bit version you have of Vista, right click Computer in the Start Menu and click Properties. You will see the bit version under the System type section.)
Download Update KB941090:
Update: Still having problems after installing the update? First, make sure that you restart Windows Mail. If you are still not able to delete messages, see Workaround Methods
