If I mail my mortgage payment of the 14th of the month, the bank receives it on Saturday the 16th, should I receive a late charge if they are closed on Saturday?

what does your contract with the mortgage company say? Late on the 15th, or late after the 15th?

Why are you mailing your payment the day before it's due? If you're going to wait till the last minute, you should at least deliver the check to make sure it's there on time and not expect the bank to give you an extra day. Everyone knows deposits made on Saturday are not credited till Monday, why should a payment be any different?!

This is a trick question, isn't it???? You don't really expect the postal service to deliver mail in two days do you?