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, select the personal appointment you want to edit in the Appointments List.
(Optional)Type a subject and a place if you haven't already done so..
Specify the start date and start time if you haven�t already done so.
(0ptional) Specify a duration. Duration can be in minutes, hours, or days.
(Optional) Type a message.
(Optional) Specify a Show As type.
Click Post on the toolbar.
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.