[BULK] Re: SORBS contact

William Herrin bill at herrin.us
Sat Jul 30 13:46:13 UTC 2011


On Fri, Jul 29, 2011 at 11:22 AM,  <Valdis.Kletnieks at vt.edu> wrote:
> On Fri, 29 Jul 2011 09:48:44 EDT, William Herrin said:
>> Correction: It's a standard way to denote that "this mail is a bounce
>> report."
>
> It's *not* just "bounce reports" (in particular, DSNs and MDNs are not
> non-delivery (bounce) messages in the sense of section 3.7, and both
> can be generated in response to *successful* deliveries).
> generated for *successful* deliveries).

Hi Vladis,

Point taken. Bounce reports, temporary failure reports and successful
delivery reports. Nevertheless, it still isn't for "other
programmatically generated mail." In fact, the next paragraph in RFC
5321 4.5.5 says:

"All other types of messages (i.e., any message which is not required
by a Standards-Track RFC to have a null reverse-path) SHOULD be sent
with a valid, non-null reverse-path."

Contrary to your claim, it's perfectly reasonable for an spam filter
in a symmetric routing scenario to discard a null return path message
that isn't unambiguously responsive to one it previously sent.


On Fri, Jul 29, 2011 at 5:52 PM, Michelle Sullivan <matthew at sorbs.net> wrote:
> Umm no...  As has been pointed out by others, but in another section
> (maybe another RFC) it says that the null return path should be used
> when a return message is not required, not desired, or it is from an
> automated system or you wish to avoid mail loops (with particular
> reference to bounce messages and mailing lists.)

Michelle,

Is your web site registration message required by a standards track
RFC to use a null reverse path?

Regards,
Bill Herrin



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William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
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