[Endymail] Improvements to S/MIME

[Wei Chuang <[e-mail]>]

Hi all,

I would like to propse that endymail list seems like a good place to
compile future IETF work for improving S/MIME (RFC5751).  I know the S/MIME
WG has been concluded for awhile, and it would be uncertain as to when such
work could be done, but perhaps if there is enough interest, then something
could be spun up.

For quiet awhile I've been wondering about two issues with S/MIME, (and if
I'm mistaken I would love to hear the solution):
1) S/MIME doesn't fully protect users mail envelope metadata.  For example
the recipient and envelope-sender must be visible to the intermediate SMTP
MTA servers or even in the clear if the transport isn't over TLS.  Could
work be done to allow for anonymize the sender and recipient to a domain
level?
2) The sender can't really specify to the recipient a forwarding/reply
security and privacy policy.  For example the sender may wish that
subsequent derivative mails be signed/encrypted, done so with a minimum
ciphers, or perhaps even request that no forwarding be done.  Should there
be work to describe a recommended security policy to the recipients?

thanks,
-Wei