To set an e-mail reminder in iCal, click on your event and the go to the View Menu and select Show Info or press Command I to do the same thing. Next, select the email option under Alarm in the Info drawer. Finally, select which e-mail address you want the reminder to go to, and how many minutes in advance that you want your reminder.
Related: Default setting for alarms in iCal, Add iCal Events In Plain English, How Do I Have Siri Reminders Appear In iCal?, events bring iCal to front, How Do I Use iCal To Allow My Staff and I To Share Calendars but Not Have My Alarms Going Off On Their iMacs?.
