Subject: Re: [ietf-smtp] BCP or similar on list validation by partial SMTP session

From: "John Levine" <[email-masked]>
Date: 1 Oct 2013 19:19:07 -0000

>> I suppose it could endorse permission passes to try to resuscitate a
>> bad list.
>
>Do you mean stuff like a monthly re-opt-in?  If not, can you explain?

Customer gives ESP a list that hasn't been used for two years, or that
is a combination of verified opt in and a shoebox full of business
cards, stuff like that.

>> Or just mail to the feeping list, and do proper bounce processing in
>> the first place.
>>
>>
>"proper" bounce processing isn't always possible, but then again the whole
>fake RCPT TO thing isn't infallible either.

If you use VERP with a cookie in the envelope that identifies the list
and the recipient, and doesn't look like the recipient's address, it
takes a pretty badly broken MTA not to produce a usable bounce.  I
realize that there are some bad addresses that don't bounce, but I
don't think a list other than one badly contaminated with bought spam
addresses is likely to have a lot of them.

>Might MAAWG be interested in converting their work into an Informational
>RFC, or maybe an Applicability Statement?

Wouldn't be the first time.

R's,
John

---

From: Rich Kulawiec <[email-masked]>
Date: Fri, 4 Oct 2013 08:20:41 -0400

I'll take a crack at it.  Bruce Gingery and I (and others) went into this
in some detail back when Verizon was doing callouts/callbacks, and I'm
pretty sure that I have still have that discussion archived.  It shouldn't
take too long to find those, re-read them, and distill them into something
applicable.  Since I'm working on a "worst practices" document anyway,
this would certainly fit.

As a side note, I don't buy into *any* method of "list validation": either
it was built properly or it wasn't.  If the former, then nothing needs to
be done; if the latter, then nothing will help: start over.

---rsk