[Exim] Using IMAP protocol to SEND email ??

OK - after struggling with the idea of SPF last night and being fairly
unimpressed with it - it got me thinking about solutions to the problem
of who relays for whom.

Obviously - you don't want anyone relaying for anyone. So clearly it
would be nice if the incoming mail process allowed you to send to the
same server. But the SMTP authentication process is totally separate for
the IMAP/POP process .....

So - since you are already connected to a server to get your email - and
you are already AUTHENTICATED to that server - then who not let IMAP do
the SENDING of the email?

There is a number of way to make this really easy to do. It would take
an addition to the standard for sending email. The first way is to have
a "SEND" command added to IMAP. You would then have to configure the
server so that IMAP can deliver message to EXIM for delivery.

The second metaphore that might be easier is to have a server side
folder called "OUTGOING" which looks like any other server side folder
but the MTA comes by and picks up the mail and sends it out.

The point is - with IMAP you are already connected to the server and
authenticated to it. So - why not let it do the sending as well and
eliminate the need for the separate step of connecting to an SMTP server
and having to use a different method of authentication?

Who likes this idea?