Did you buy the ticket just today? If so, I believe even E tickets have 24-hour cancellation (really midnight of the day after booking).
During the reservation process on delta.com the E fares are in a separate column from other main cabin fares. If you select an E fare a large pop-up window tells you the restrictions and has you check an acknowledgement.
Last edited by CarmenOM; Dec 17, 2016 at 2:57 pm