Before all the days of technology, mail is the main source of communication all over the world. It is beneficial not just for personal use but also for the business who send notices through letter or reminders to clients. There are many documents also that is needed and they could be sent through the mail so that they can reach the intended receiver. Mail has been delivered in bulk and even by trucks to different locations every day. Sometimes you have to wait for one month to receive a letter.
They developed telegram to deliver an urgent and emergency message to someone with costs that is higher than the normal mail. When the telephone was invented the mail still was not that affected but there was an effect when cell phones were invented. It is a cheaper and faster way of communication. You can use it for overseas calls and local calls and you can use it anytime as long as you have loaded. It did not stop there but the rise of social media did a great effect.
As the use of social media spread all around the world and it has many benefits and advantages so it was more preferred than the mail. It was just used by the different businesses and other government offices who have still to deliver important documents and give notifications that are considered legal. Even if the use of it was dramatically decreased but it is not yet dead.