mail vs When comparing mail vs other shipping services, the main differences revolve around cost, delivery time, and reliability. Traditional mail services, such as those offered by USPS, are often more affordable but can be slower and less reliable, particularly for international deliveries. On the other hand, private couriers like FedEx and UPS typically offer faster delivery and more reliable tracking services, albeit at a higher cost. The choice between mail and private services largely depends on the urgency and value of the package being sent.