[Mimedefang] Re: On pinheaded ISP's (sort of OT)

[David F. Skoll]

Scott Silva wrote:

> If you can't reject during the initial SMTP phase, then your NDR's of spam,
> with their possible forged envelope addresses, will also be spam. So, if you
> can't drop at the initial conversation, or it is relayed from a backup MX, it
> is your message, and your problem. Just don't generate NDR's. If you can't
> return at SMTP, you will need to drop it.

I disagree.  Backscatter is bad, but turning e-mail into something
totally unreliable will damage it more than spam has.  Silently
dropping mis-addressed e-mail messages is a violation of a MUST
requirement of a standards-track RFC.  It's not something you should
do lightly (or indeed at all).

Sometimes, you have no choice but to generate an NDR.  You might in
all good faith accept mail for a recipient only to find out he's set
up a .forward file and the destination server refuses the mail.
So while we should all strive to minimize NDRs, we can't eliminate
them.

Regards,

David.