How to Assign Tasks in Outlook 2013
Type the name of the person to whom you’re assigning the task in the To box, just as you would with an e-mail message.
The person’s name appears in the To box.
Click the Send button.
The task is sent to the person to whom you’ve assigned it.
The person to whom you addressed the task gets an e-mail message with special buttons marked Accept and Decline. When the person clicks Accept, the task is automatically added to his or her Task list in Outlook. If the person clicks Decline, that person is fired. Okay, just kidding, the person is not actually fired. Not yet, anyway.