Outlook Outbox

[legal girl]

When setting e-mails to be sent later they go into my Outbox. However, they are showing as "unread" in the Outbox, which means they don't get sent at the time set. At the moment I have to go into the e-mail in the Outbox, click "send" and then the message shows as unread and is then sent at the allocated time. This didn't happen until my hard drive was replaced recently - does anyone know which setting I need to change so I don't have to do this every time?