I have boldly stated that there is no way to 'write protect' an e-mail, but want to be sure of my ground.
Surely if Joe Bloggs receives an e-mail from me (or my e-commerce site or a web application written by me) saying - "I will sell you X for $10 ", he COULD modify that price to, say, $9, and forward it to someone or save te e-mail, but so what ?
The original e-mail will always be accesible and traceable on mail servers and a copy in mail clients of all recepients.
So therefore, there is no need to do this - and anyway it is not possible.
Is this true ?