Re: Unhappy with the complexity of pop-imap-downgrade

--On Wednesday, February 08, 2012 12:13 +0100 Arnt Gulbrandsen
<arnt <at> gulbrandsen.priv.no> wrote:

>...
> As far as I could tell, none of the IMAP, POP, SMTP or
> Submission extensions involve a promise on part of the server
> to support IMAP/POP downgrading. But I find that a little
> surprising, so maybe there is a promise I've overlooked?

The problem is that the server can't know and the promise should
not be necessary in the long term (everything past the delivery
server EAI-capable).  Trying to draw a picture that covers all
of the cases, including closely-connected message stores and
ones to whom messages are passed (via LMTP, shared NFS-like
storage, or otherwise), POP/IMAP clients with varying
capabilities, and so on. is really illuminating about how many
cases there are, what information has to be available in what
places, etc.  A delivery server _could_ promise to always
downgrade a message before depositing it in or transferring it
to the the mail store but that is exactly the behavior we want
to discourage in order to favor EAI-capable mail stores.

    john