Re: per user post-data rejects, Processing after the end of DATA

ned+ietf-smtp(_at_)mrochek(_dot_)com wrote:

> > So if they've decided it's spam, what's the problem with 
> > throwing it away?
> The same problem as always: False positives. While I think the various
> admonitions we have in various documents that try and discourage 
> silently dropping messages are unrealistic, the fact remains that 
> silent draps create reliability issues. Rejects address this issue and 
> are preferable, as long as they don't create additional issues.
>                 Ned
+1.

As a public note for the unaware, the new RFC 5321 for the first time 
ever, has "cracked opened the door" with new SMTP semantics allowing 
or provides a rationalization for discarding of mail under 
"reasonable" circumstances.
IMV, having new official RFC mail protocols specifically designed for 
this purpose is rational and reasonable, such as RFC 5617 (ASDP) with 
its DKIM=DISCARDABLE policy. As long as the ADSP domain publicly 
exposes this self-asserted policy, I don't think it contributes to 
false positives discarding of accepted but zero false positive proof 
for ADSP violating mail.
However, one implementation question is when a DATA level ADSP based 
(55x) rejection can also serve the same purpose for ADSP domains.
Currently this only seems to be a problem for DKIM resigners ignorant 
of errant or spoofed ADSP protected mail submissions.  Murray's Mail 
List Manager (MLM) draft proposal hopes to provide, IMV, "sound 
protocol consistency" guidelines in this area for DKIM+ADSP compliant 
List Server and SMTP receiver developers to consider.
--
Sincerely

Hector Santos
http://www.santronics.com