Stage 1: “What is this e-mail thing?”
Stage 2: “Whee! So funny! Forward to everyone!!!”
Stage 3: “I am going to kill the next forward propagating worm”

Related: Today, I sent the following to an email list I am on.

After Godwin's Law, I propose:

"As the age of an email group increases, the probability that someone sends a senseless forward approaches 1."