RE: SMTP or MIME in Strawman OPES Charter

> 
> 	Jfc seems to re-visit, perhaps unknowingly, a very important
> charter-related question that we must finish discussing. Please see
> 
> 	http://www.imc.org/ietf-openproxy/mail-archive/msg02979.html
> 
> for the start of the thread. In
> 
> 	http://www.imc.org/ietf-openproxy/mail-archive/msg02982.html
> 
> you said "Similar to what we did in the first charter, we can make
> SMTP the prime goal which we'll have to provide a solution for, but we
> can first explore the feasibility of a general "email/MIME" profile
> (and maybe include an explicit charter item for such exploration)."
> 
> The above direction was supported by Abbie and myself, without
> objections. Can we go down that path and include an exploratory
> charter item instead of starting with SMTP? It may also simplify
> solving the agent-dependency problem for SMTP. We can be more vague
> about SMTP if we have to do MIME first!
> 

In earlier discussions we found that MIME is a good fallback when
negotiating profiles and no match for a more detailed application
is found. So, exploring a MIME profile indeed has some value.

On the other hand I think that we must concentrate on SMTP if we
want to do OPES for email not MIME or any other email protocol.

Most messages in the Internet are transferred using SMTP. POP
and IMAP are used to fetch them from a mailbox but they reach
the mailbox usually via SMTP.

And the SMTP dialog has information that is needed as meta data
in addition to the MIME message for effective filtering, for
example if you want to check the recipients of a message you
better ignore the MIME header but look at the RCPT TO parameters
from the SMTP dialog.

In addition we should consider that some OPES services may want
to adapt the SMTP dialogs, for example control the relay behavior
of an MTA (decide which sender is allowed to send to which recipients).
That is definetly beyond MIME message filtering.

So, I think we should concentrate on OCP/SMTP. As adapting MIME
messages is the most important sub part of that we may want to
explore that first and design the profile in a way that allows to
create an OCP/MIME profile easily by simply deleting all parts that
are beyond the MIME message part.

Regards
Martin