Mail Server best practices - was: Pandora's Box of new TLDs

Rich Kulawiec rsk at
Sun Jun 29 11:22:33 UTC 2008

On Sat, Jun 28, 2008 at 05:56:23PM -0400, Jean-Fran?ois Mezei wrote:
> The original mantra of either discarding the email during SMTP
> conversation, or sending a non delivery notification should be strictly
> adhered to. When email becomes unreliable (thanks to microsoft), people
> stop using it.

I agree with your sentiments -- that notification is essential in order
to provide a heads-up about problems (and that once problems are noticed,
cooperation is essential in order to fix them).  But mail should never
be discarded without notice, and NDN's should never be sent (MTA-to-MTA,
which is a different matter than MSA-to-MTA): it should either be accepted
(and delivered) or rejected (and not delivered).   This provides accurate
notification to the sending MTA of the disposition of the message, and it
avoids outscatter spam.  Of course, this doesn't do anything to elicit
cooperation from either side, but at least it makes problems visible
(provided nobody's MTA mangles or drops the reject notice) so that there's
a decent chance of figuring *whose* cooperation is needed.


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