[Mimedefang] Deadline for SPF records *long w/morbid horoscope*

[Graham Dunn]

On Mon, Aug 09, 2004 at 11:17:41PM -0400, Jeff Rife wrote:
> On 9 Aug 2004 at 21:03, Kevin A. McGrail wrote:
> 
> > > If the receiving MX servers always knew all valid recipient addresses
> > > *at (E)SMTP connection time*, then there would be no bounces...only
> > > rejections.
> > >
> > > This solves the problem without introducing anything new to (E)SMTP.
> > 
> > At the core, this solution ignores the concept and purpose of a backup MX
> > which is a reality and necessity for many companies where email is critical.
> 
> There is no reason a backup MX server can't know if an address is valid 
> or not.

How about "scaling"? I'm pretty sure my ISP will run (screaming, no
doubt), from a scenario in which they rely on their customers to keep
their list of valid addresses current.

How about "MS Exchange"? :]

Graham