If you are not available for meetings, schedule a posted appointment for those times. When another user includes you in an appointment and does a busy search, the user can see that you are not available at those times, but can still schedule over your appointment.
In your Calendar, click the appointments list.
Type a subject and a time and start time.
Press Enter to post the appointment.
Posted appointments are placed in your Calendar on the date you specified. They are not placed in your Mailbox or in any other user�s Mailbox.