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Re: Spam filtering bcps [was Re: Open Letter to D-Link about their NTP vandalism]

  • From: Valdis.Kletnieks
  • Date: Wed Apr 12 14:19:46 2006

On Wed, 12 Apr 2006 10:16:53 PDT, Steve Thomas said:
> > I haven't seen any succinct justification for providing a
> > 550 message rejection for positively-identified spam versus
> > silently dropping the message. Lots of how-to instructions
> > but no whys.
> RFC 2821?
>   ...the protocol requires that a server accept responsibility
>   for either delivering a message or properly reporting the
>   failure to do so.

Elsewhere in 2821 (6.1, to be specific):

   When the receiver-SMTP accepts a piece of mail (by sending a "250 OK"
   message in response to DATA), it is accepting responsibility for
   delivering or relaying the message.  It must take this responsibility
   seriously.  It MUST NOT lose the message for frivolous reasons, such
   as because the host later crashes or because of a predictable
   resource shortage.

OK? Got that? You '250 OK' it, you got a *serious* responsibility.  Losing the
message because the whole damned machine crashes is considered a frivolous reason.

And throwing it away because you don't like the way it looks is OK?  Man,
you're in for some severe karmic protocol payback down the road... ;)

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