General

memhole headers have to be first mime part within email/protected area.
protected email = memory hole signed/encrypted email ??? first memhole headers found within protected part of email should bubble out and be displayed to the user.

Signed

Memhole for signed message easiest to accomplish, presentation avsilable already in every mua
Select headers to protect when signing:
From
To, CC
Date
Reply-To
Message-ID
References, In-Reply-To
memoryhole header line, including memhole version
include flag if first existing rfc822 part inside protected area should be interpreted as force-display header
Order to interpret each line has protection info, starts with 0 exclude content-type! just from top level how to resolve differences

show that headers are memhole headers somehow
show memhole headers accordingly to mua style of showing (non) tampered signatures/emails
when receiving emails with signed and unsigned parts, user should be able to show unsigned/"weird" parts of email. by default only display signed parts

memhole is designed to ensure that the mime body of email is signed! (or at least some specific parts are signed)

including protected headers in encrypted part preempts splicing attack (combining headers from mail a and encrypted mail b)

Choose by yourself which headers to force-display and which are stripable when encrypting:
From
To, CC
Date
Reply-To
Message-ID
References, In-Reply-To
memoryhole header line, including memhole version

memhole headers may only appaer in the first protected mime part or in the force-display section (text/rfc-822headers part)

include/protect conten-description in signed emails?
email manifest/separate headers? -> discussion about manifests should be started/continued within mailing list
how do i detect stubbing securely?
non-stripped-encryption-protected-headers: how to display?