Are corporate emails valuable?

Metcalfe’s law states that the value of a network is proportional to the square of the number of users of the system (n²). First formulated by Robert Metcalfe in regard to Ethernet, Metcalfe's law explains many of the network effects of communication technologies and networks such as the Internet and social networking.

Having said that, I think we all can agree on Companies need to be better in sharing corporate emails. Of course you have to make some rules about how and what to share, but the acceleration of value to the Company from sharing the knowledge that recites in the Company volume of emails will surprise you. Metcalfe’s law is quite simple if the number of nodes (n) is zero the value to the Company is zero.

Maybe it is too simple to use Metcalfe’s law towards the use of emails in a Company or is it?