Communication disguises

Reading about the self inflicted problems of senior officers in the Army on the other side of the pond, who were thinking with their genitals,  I have learned that one of the involved couples used a nifty way of communicating by e mail.

To avoid having the messages ping back and forth through the ether (or along a cable), which might mean they could be intercepted and read, they instead used a single e mail account jointly and wrote a message and then saved it in Drafts. The other party could then come along, log in and read the mail and reply, once again saving it as a draft and so on.

Since we both shy away from texts and work e mails which refer to spanking and discipline I might suggest this as a means of communication between my wife and I. 

Does any reader use anything similarly discrete to send messages which you would be embarrassed to either mis-direct or have discovered by some IT supervisor at work?

Of course being discovered for the crime of misuse of company e mails might have its own story to tell, in terms of disciplinary procedures, but odds on  the Super  would not be as attractive as this.