The point of running your own email and dns server is so that you are a peer on the network.[1]
This is important and is becoming lost in the current era of Internet adoption.
By many measures the Internet is the largest cultural and commercial force in the world today and by an accident of history, the researchers at (D)ARPA gave us a network that allowed normal citizens to be peers on the network.
Don't lose this.
[1] As opposed to, for instance, the telephone network. You can own your own domain and perform the first level of network interaction on your Internet systems, but the analogy on the phone network (owning your own phone number and controlling the first touch from other networks) by creating a CLEC is administratively and financially ($100k +) impossible.