I'm not sure why you are being downvoted because this is a very legitimate question. Fortunately it's not hard to see that email, and Tomlinson's contributions

I'm not sure why you are being downvoted because this is a very legitimate question. Fortunately it's not hard to see that email, and Tomlinson's contributions, were incredibly novel and have shaped a lot of "good parts" of the internet today. Although obviously email was conceptually based on a very old notion of communication, embodied, as you point out, by many media that came before it, it had to solve a few small, specific problems inherent in moving messages from one system to another via a simple network protocol. The use of the "user@domain" notion of identity seems mundane today, but in some important ways it was a huge breakthrough in the way that people thought about humans and the systems that need to work in order for them to be contacted.