In an open item, on the Appointment or Meeting tab, in the Options group, in the Reminder drop-down list, select the amount of time before the appointment or meeting when you want the reminder to appear. To turn a reminder off, select None.
For e-mail messages, contacts, and tasks
Tip You can quickly flag e-mail messages as to-do items by using reminders. Right-click the Flag Status column in the message list. Or if you have the message open, on the Message tab, in the Tracking group, click Follow Up, and then click Add Reminder.
