Just a comment on saving drafts technique. That applies to using web mail, and recipient(s) is supposed to share the same web mail account. It can work, but there is still network traffic between PC (or other device) on which the message is written and web server which hosts the web mail service.  That traffic can be monitored, too.

 

I suppose it worked in the beginning, but became as risky as anything else later.  The participants would be safer if they used public terminals, instead of private PC's or phones with web capability, but public terminals (like Internet cafe, or public wireless access point) can be monitored, as well.

 

DG