etherspace 

The space where emails cross when two people email at the same time, are about the same thing and are in agreement and unknowing to one another.

No need for us to talk about this, we keep crossing in etherspace!

etherspace by johnsmith12345678900 December 5, 2011

ethersphere 

Derived from the more specific word, ethernet, to a more general meaning for the intangible that is the internet or non-handwritten, non-oral communication.

I sent that email, but it probably got lost somewhere in the ethersphere. ether

ethersphere by pantaleimona April 1, 2010