Re: You lost me at....
This is one of the alleged military approach to sanitising messages, the email receiving/sending machine is destroyed each day. (Re-imaged from sd-card or similar for a VM state) Hence there's no terabyte of old emails in an inbox. Hence if you wish to keep a sent or received mail, either print it out or you could always forward it to your super-secret second email account that doesn't get phish/virus attacks.
Richard Stallman gets his emails delivered to a friend who prints the interesting ones out & posts-them, allegedly.
Why should a single obfuscated link in an email lead to all your data being cryptolocked? That's a spectacularly broken system, hence extraordinary measures are needed to defend users.