Re: [dispatch] SMTP Code for Undesirable Messages

["Murray S. Kucherawy" <[e-mail]>]

On Fri, Dec 17, 2021 at 9:05 AM Brotman, Alex <Alex_Brotman=
[e-mail]> wrote:

> I've been wondering if it may be beneficial for a mailbox provider to be
> able to signal back to the sender that the message is being accepted, but
> is undesirable based on some criteria.  The idea would be that a provider
> may evaluate some characteristics of the message, and before issuing a "250
> Ok" have already determined the message would be routed to the spam
> folder.  Something as simple as:
>
> 255 Ok - Routing to spam folder
>
> This would likely need some "Security Considerations" section about how
> informing a malicious entity may be undesirable.  I'm willing to write this
> up as a proposed draft, though I'm not entirely sure where to direct that
> draft.  Thank you for any advice you could provide.
>

Two things, one substantive and one procedural:

(1) On procedure: This might be better raised on either the SMTP mailing
list or the ART mailing list.  DISPATCH is mostly for talking about live or
proposed work items, like when there's a draft ready to bring to the table
for disposition.

(2) On substance: Why not register an enhanced status code for this instead
of a new SMTP reply code?  See
https://www.iana.org/assignments/smtp-enhanced-status-codes/smtp-enhanced-status-codes.xhtml
and the RFC it references.

-MSK