E. Interline Carriage
Delta will be responsible for furnishing of transportation only over its own lines. When Delta undertakes to issue a ticket, check baggage, or make any other arrangements for transportation over the lines of any other carrier (whether or not such transportation is part of a through service), Delta will act only as agent for such other carrier and will assume no responsibility for the acts or omissions of such other carrier.
and
Delta will use its best efforts to carry the passenger and baggage with reasonable dispatch. Times shown in timetables or elsewhere are not guaranteed and form no part of this contract. Delta may without notice substitute alternate carriers or aircraft, and may alter or omit stopping places shown on the ticket in case of necessity. Schedules are subject to change without notice. Delta is not responsible or liable for making connections, or for failing to operate any flight according to schedule, or for changing the schedule or any flight.
Directly from DL's CoC.