How long before flight leaves should I be at the airport?

[Krisby10]

Our last day at Disney we will be at Epcot - and our flight will probably leave at 6pm -- how much time do I need to give ourselves to get there and ready to leave? I have no clue how long things take (only flown a few times before). I obviously dont want to miss our flight. We will probably have all our luggage back at POP and use the magical express option so everything should be already at the airport when we get there or however that works.

Thanks
Kristie

[Lewisc]

You don't have a choice, DME will give pick you up approximately 3 hours before your flight. The day before you leave you'll get a letter that will tell you your pick up time.