what is the difference between express mail and priority mail

what is the difference between express mail and priority mail lies in the delivery speed and cost. express mail is a faster, more expensive service, offering guaranteed next-day or 2-day delivery, depending on the destination. It is ideal for urgent shipments that need to arrive quickly. On the other hand, priority mail is a more affordable service, with delivery times ranging from 1-3 business days, but it does not guarantee the same speed as express mail. Both services come with tracking and insurance options, but express mail is designed for time-sensitive shipments, while priority mail is a reliable option for less urgent deliveries.