Re: FAQ: SMTP Message Submission to Proposed Standard

["Perry E. Metzger" <perry@xxxxxxxxxxxx>]

Chris Newman writes:
> SMTP Submit FAQ:
> 
> (1) Why is this urgent now?
> 
> The email industry desperately needs an authenticated submission
> service.

Given that relaying isn't authenticated, this strikes me as
unimportant. Remember that SMTP is not an end to end protocol but a
hop-to-hop protocol.  This means that the only real security that can
be provided for it is object security, like S/MIME.

Authentication of submission is nice, therefore, but not "critical".

> (2) Why have a separate submit port?
> 
> Submit and relay are separate services.  Submit needs to have more
> stringent validation of content,

I dispute that. If you can forge a submission via forged messages to
the relay, then why will stringent validation on ingress help?

> (4) Why doesn't security protocol X solve all the problems?
> 
> MTA/MUA vendors have to sell products which work out of the box.  That
> means they can't insist on the installation of custom TCP/IP stacks

TLS requires no custom hacks. Its layered on top of TCP, and it is
standards track.

> the purchase of certificates from Verisign before working.

Not necessary, either.

Perry