E-mail is very convenient these days, especially in work. It’s faster than regular mail. And it’s cheaper than phone call. E-mail is useful because is quicker and easier. And you can send attached for another people.
On the other hand, you get a lot of spam and virus. There’s nothing worse than spam when you’re really busy or virus when you need use you computer.
However, I like more e-mail than phone call, because you prove you say and talk for another person.