Below are the reason given for writing email service are used:
Email is a quick way to communicate. Sending a message is as simple as clicking a button once you've done writing it. Email is sent, transported, and viewed almost instantly, especially if an email system is connected to the network.
Email is easy to use. It's simple to use. Composing, sending, and receiving messages is straightforward once your account is set up.
Messages that have been sent and received can be safely kept and looked through. It's far easier to go through old email communications than it is to look through old paper notes.