Subject: TMDA in Front of WG Mailman

From: "Fuller, Barbara" <[email-masked]>
Date: Mon, 9 Apr 2007 09:32:42 -0400

Dear IETF WG Chairs,

I am resending this message because the original one had an incorrect
"Subject" line.

Barbara
------------------------------------------------------------------------
-
Many of you have indicated that your WG mailing lists hosted at ietf.org
receive large volumes of spam, which makes moderating the lists
difficult.  The Secretariat has been experimenting with inserting
"Tagged Message Delivery Agent" (TMDA) in front of Mailman lists, and
the experiment has been quite successful in reducing the number of spam
message that reach these lists.  Therefore, we would like to offer this
service to all WG chairs who are interested in taking advantage of it.

The measures used by TMDA to thwart spam include:

(a) Whitelists: accepting mail from known, trusted senders.

(b) Blacklists: refusing mail from undesirable senders (i.e., known
spammers).

(c) Challenge/Response: allowing unknown senders who are not on the
Whitelist or Blacklist the chance to confirm that their messages are
legitimate (at which time they are added to the Whitelist).

For IETF, the Whitelist includes every address that is subscribed to any
IETF mailing list, and the Blacklist includes any addresses that the
list administrators request be placed on them (i.e., because of repeated
spamming).  A sender who is new to the IETF would need to respond to the
challenge only once in order to be Whitelisted.

We plan to implement TMDA on the WG mailing lists beginning on Monday,
April 16th, and hope to complete the process in approximately one month.
If you do *not* want TMDA inserted in front of your WG list, then we
would appreciate hearing from you by no later than Friday, April 13th.
If we do not hear from you by 5:30 ET on that date, then we will assume
that you want us to proceed.  Each list administrator will be notified
by e-mail when TMDA had been inserted in front of his or her WG mailing
list.

Once again, this program is voluntary, so please be sure to let us know
if you wish to "opt out."

Best Regards,

Barbara Fuller
for the IETF Secretariat.

---

From: Eric Rescorla <[email-masked]>
Date: Mon, 09 Apr 2007 06:44:04 -0700

At Mon, 9 Apr 2007 09:32:42 -0400,
Fuller, Barbara wrote:
> 
> [1  <text/plain; us-ascii (quoted-printable)>]
> Dear IETF WG Chairs,
> 

This sort of change seems like a program which would be better to
be offered on an opt-in basis.

> if you wish to "opt out."

Please do not turn this feature on for [email-masked]

-Ekr

---

From: "Steven M. Bellovin" <[email-masked]>
Date: Mon, 9 Apr 2007 10:44:27 -0400

On Mon, 09 Apr 2007 06:44:04 -0700

> be offered on an opt-in basis.
I agree.  TMDA irritates a lot of people; I know many folks who
flat-out refuse to deal with it.

It's also unclear to me what problem it solves for us.  Mailman already
has whitelists and blacklists.  The only thing it would seem to
accomplish is to permit posts by legitimate people who aren't
subscribed to any IETF lists at all.  I suspect that such posts are
very few in number.  We'd be better off, I think, just sending a bounce
message saying "subscribe to any IETF list at all if you want to
post".  (We could even have a null mailing list whose sole purpose is
to qualify you to post anywhere, but which carries no traffic of its
own.)
> 
> > Once again, this program is voluntary, so please be sure to let us
> > know if you wish to "opt out."
> 
I'll check with my co-chair, but I'm inclined to opt out for ipr-wg.

		--Steve Bellovin, http://www.cs.columbia.edu/~smb

---

From: Russ Housley <[email-masked]>
Date: Mon, 09 Apr 2007 10:46:59 -0400

Eric:

We have done some experiments, and found it to very effective with 
almost no use of the challenge/response mechanism.  The use of the 
whitelist composed of members of all ietf.org mail list really keeps 
this to an absolute minimum.  I agree with the approach being taken 
by the Secretariat.

Russ

---

From: Rob Austein <[email-masked]>
Date: Mon, 09 Apr 2007 11:04:11 -0400

> to qualify you to post anywhere, but which carries no traffic of its

TMDA in the kind of configuration I suspect the Secretariat is talking
about here attempts to solve two problems:

1) Spam posts to the list by non-subscribers;

2) Spam sent to the list administrators via the list -owner address.

Steve's suggestion for (1) is fine for IETF mailing lists if the
legitimate users of that list agree on that policy.  It doesn't work
so well for cases like the IESG and IAB mailing lists.

Full disclosure: I think I was the person who originally proposed a
TMDA + Mailman solution (at least, I proposed such a solution to the
Secretariat more than three years ago).  I originally proposed it as
part of an attempt to get spam filtering for the IAB list under
control.  I've been using a configuration like this on some non-IETF
lists that I run, and it has worked out well for those lists.  YMMV.

---

From: "Steven M. Bellovin" <[email-masked]>
Date: Mon, 9 Apr 2007 11:17:53 -0400

On Mon, 09 Apr 2007 11:04:11 -0400
Rob Austein <[email-masked]> wrote:

> > It's also unclear to me what problem it solves for us.  Mailman
> > already has whitelists and blacklists.  The only thing it would
> > seem to accomplish is to permit posts by legitimate people who
> > aren't subscribed to any IETF lists at all.  I suspect that such
> > posts are very few in number.  We'd be better off, I think, just
> > sending a bounce message saying "subscribe to any IETF list at all
> > if you want to post".  (We could even have a null mailing list
> > whose sole purpose is to qualify you to post anywhere, but which
> > carries no traffic of its own.)
> 
Barbara's note said

	For IETF, the Whitelist includes every address that is
	subscribed to any IETF mailing list

That means that any IETFer would be able to email the IAB and IESG.

---

From: Rob Austein <[email-masked]>
Date: Mon, 09 Apr 2007 11:26:00 -0400

> That means that any IETFer would be able to email the IAB and IESG.

Something got lost in translation.  Yes, Barbara's message implied
that the TMDA whitelist would allow any subscriber to any IETF list to
post to the IAB and IESG lists (which is good).  What I meant was that
a Mailman subscriber-only posting restriction wouldn't be a good
answer for the IAB and IESG lists, which is why TMDA is a good fit for
those lists in particular.

---

From: Paul Hoffman <[email-masked]>
Date: Mon, 9 Apr 2007 09:41:44 -0700

At 10:44 AM -0400 4/9/07, Steven M. Bellovin wrote:
>very few in number.

These are good points. If Mailman can handle whitelisting people 
without TDMA, it would make sense to add all people subscribed to any 
IETF list to the whitelist for every IETF list.

FWIW, I have been doing this whitelisting (albeit with handmade tools 
for Majordomo) for a few years on the lists that IMC and VPNC hosts. 
At this point, approximately one legitimate message a month for all 
the lists we run get caught in the "needs to be whitelisted" trap. If 
I had the entire set of IETF lists to work from, I am sure that 
number would be even lower.

>We'd be better off, I think, just sending a bounce

That seems like a good solution for any list that doesn't want to 
have the TDMA in front of it.

--Paul Hoffman, Director
--VPN Consortium

---

From: Colin Perkins <[email-masked]>
Date: Mon, 9 Apr 2007 18:03:43 +0100

On 9 Apr 2007, at 15:44, Steven M. Bellovin wrote:
> On Mon, 09 Apr 2007 06:44:04 -0700 Eric Rescorla  
> <[email-masked]> wrote:

Fully agreed. TMDA is more annoying than the spam it tries to  
prevent. No thank you.

Colin

---

From: "Fuller, Barbara" <[email-masked]>
Date: Mon, 9 Apr 2007 13:22:30 -0400

Hi Colin:

Please confirm that you do not wish to have TMDA inserted in front of
the following lists:

[email-masked]
[email-masked]

...as well as in front of any other lists that I may have missed ;-)

Thanks

Barbara

-----Original Message-----
From: Colin Perkins [mailto:[email-masked]] 
Sent: Monday, April 09, 2007 1:04 PM
To: Ray Pelletier; [email-masked]; Fuller, Barbara
Cc: Working Group Chairs
Subject: Re: TMDA in Front of WG Mailman

Colin

---

From: Colin Perkins <[email-masked]>
Date: Mon, 9 Apr 2007 18:28:05 +0100

Barbara,

I don't want TMDA inserted in front of any IETF lists, however those  
are the groups for which I'm co-chair.

Colin

-- 
Colin Perkins
http://csperkins.org/

---

From: Melinda Shore <[email-masked]>
Date: Mon, 09 Apr 2007 14:33:38 -0400

Please don't put it in front of the midcom working group
mailing list, either.

Thanks,

Melinda

---

From: Pete Resnick <[email-masked]>
Date: Mon, 9 Apr 2007 16:55:49 -0500

On 4/9/07 at 6:44 AM -0700, Eric Rescorla wrote:

>This sort of change seems like a program which would be better to be 
>offered on an opt-in basis.

Indeed. Barbara, given the number of chairs you've heard opt-out in 
the first 12 hours, you should really make this an "opt-in" thing: 
Only turn on TMDA for those chairs who want it turned on.

pr
-- 
Pete Resnick <http://www.qualcomm.com/~presnick/>
QUALCOMM Incorporated - Direct phone: (858)651-4478, Fax: (858)651-1102

---

From: "Glen Zorn \(gwz\)" <[email-masked]>
Date: Mon, 9 Apr 2007 16:47:13 -0700

Eric Rescorla <mailto:[email-masked]> allegedly scribbled on
Monday, April 09, 2007 6:44 AM:

...

>> If we do not hear from you by 5:30 ET on that date, then we will
>> assume that you want us to proceed.  Each list administrator will be
>> notified by e-mail when TMDA had been inserted in front of his or her
>> WG mailing list.
> 

I agree completely.

...

---

From: "Randy Presuhn" <[email-masked]>
Date: Mon, 9 Apr 2007 23:00:25 -0700

Hi -

We have a problem with someone whose posting privileges have
been revoked continuing to try to post to our WG mailing list.  Fortunately,
the current mailman mechanisms block those postings, either as
"moderated subscriber" postings or as "non-subscriber" postings.
However, since this person uses a large repertoire of posting addresses,
and is still subscribed to some other IETF mailing lists, I am concerned
that using TMDA would allow one of these alter egos to post to our mailing
list.  Consequently, as co-chair of the ltru WG, I'am requesting that TMDA
*not* be activated for the [email-masked] mailing list.

Randy

----- Original Message ----- 
From: "Fuller, Barbara" <[email-masked]>
To: <[email-masked]>
Cc: <[email-masked]>; <[email-masked]>; "Russ Housley" <[email-masked]>; "Lindberg,Jon"
<[email-masked]>
Sent: Monday, April 09, 2007 6:32 AM
Subject: TMDA in Front of WG Mailman

Dear IETF WG Chairs,

Barbara

Best Regards,

Barbara Fuller

---

From: Henrik Levkowetz <[email-masked]>
Date: Tue, 10 Apr 2007 09:42:21 +0200

> *not* be activated for the [email-masked] mailing list.

The way I understand the proposed mechanism, the current Mailman setup and
capabilities will remain in place, untouched, behind the TDMA, so you
can still do exactly the same filtering in Mailman as you do today.

The only effect of running TDMA as described would be that the very first
post from somebody who is not subscribed to *any* IETF mailing list would
have to be confirmed by the poster.  For the 4 lists I administer, this
would, as far as I can tell, correctly handle 100% of the incoming traffic
over the last year or so, at the cost of requiring a non-IETF poster to
to confirm his/her first message.  ("Non-IETF poster" in this context being
somebody who isn't subscribed to any IETF mailing list and has not posted to
any IETF mailing list earlier).  

I think I can recollect 2 valid on-topic non-IETF posts over the last years,
and a couple of more first-time conference announcement posters announcing
conferences even faintly related to the list.

To me the cost of having those few people confirm their first post is an
acceptable trade-off for reducing the time I have to spend, every day,
throwing away spam aimed at the lists.

Barbara, I'd like to opt-in for the mip4, mdir, tools-discuss and tools-team
lists.

	Henrik

---

From: Magnus Westerlund <[email-masked]>
Date: Tue, 10 Apr 2007 11:46:31 +0200

Hi,

I am one of the IESG lists mailman admins and I am very, very happy with 
TMDA. It reduces the number of SPAM in the mailman admin queue to one in 
10 real messages. I know the IESG list is special due to hits high count 
of non subscriber postings. However, receiving 1 spam per week instead 
of the normal 20-30 per day makes life much more easy and reduces the 
risk of missing real messages.

So far I haven't seen a single complaint about the fact that TMDA has 
been in place in front of the IESG list for a number of weeks now.

So please do put it in place on the TSVWG list.

Cheers

Magnus Westerlund

IETF Transport Area Director & TSVWG Chair
----------------------------------------------------------------------
Multimedia Technologies, Ericsson Research EAB/TVM/M
----------------------------------------------------------------------
Ericsson AB                | Phone +46 8 4048287
Torshamsgatan 23           | Fax   +46 8 7575550
S-164 80 Stockholm, Sweden | mailto: [email-masked]
----------------------------------------------------------------------

---

From: Derek Atkins <[email-masked]>
Date: Tue, 10 Apr 2007 09:49:29 -0400

> Fully agreed. TMDA is more annoying than the spam it tries to  

Completely agreed.  I consider TMDA messages SPAM, and indeed MY
spamfilters block many TMDA messages.

I'd rather see the Secretariat spend time on a tool that allows
you to auto-whitelist based on subscription to ANY IETF list
instead of using TMDA.

> Colin

-derek

-- 
       Derek Atkins                 617-623-3745
       [email-masked]             www.ihtfp.com
       Computer and Internet Security Consultant

---

From: Henrik Levkowetz <[email-masked]>
Date: Tue, 10 Apr 2007 17:24:29 +0200

Hi Derek,

> you to auto-whitelist based on subscription to ANY IETF list

Ehh?  Barbara's mail indicated that exactly this is part of the
proposed installation: subscription to *any IETF* list puts you
on the TDMA whitelist -- this being the case, most lists which are
currently run with a Mailman configuration of 'hold messages
from non-subscribers' can be changed to permit postings from
non-subscribers; which gives you the tool you're asking for
above...

Are people reacting emotionally to the acronym TDMA, without
realizing the effect of the particular installation and configuration
proposed here?

Personally I find the use of TDMA in front of personal email
addresses offensive, and people who use it won't get mail from
me; however I find the use and setup proposed here benign.

	Henrik

---

From: "Drage, Keith \(Keith\)" <[email-masked]>
Date: Tue, 10 Apr 2007 18:11:38 +0200

Some clarification please.

At the moment, a number of mailing list members have multiple addresses
from which they post.

We have dealt with this by whitelisting the alternative addresses in the
mail server (rather than creating separate accounts with no mail). 

Does the proposal automatically take into account these whitelisted
addresses (and automatically add them to the TMDA whitelist), or is
there another preferred manner of handling such users?

(I would note that current valid non-member postings to [email-masked]
(i.e. those that appear in the moderator queue) are currently less than
1 in 100, and many of these that are passed by myself should in fact be
sent to the alternative sip implementors list that exists. This means
that currently there is a good change that such mails get deleted
because they are lost in the noise - we currently receive 200 to 300
such held postings a week)

Regards

Keith

________________________________

	From: Fuller, Barbara [mailto:[email-masked]] 
	Sent: Monday, April 09, 2007 2:33 PM
	To: [email-masked]
	Cc: [email-masked]; [email-masked]; Russ
Housley; Lindberg,Jon
	Subject: TMDA in Front of WG Mailman

	Dear IETF WG Chairs,

	I am resending this message because the original one had an
incorrect "Subject" line.

	Barbara

	Many of you have indicated that your WG mailing lists hosted at
ietf.org receive large volumes of spam, which makes moderating the lists
difficult.  The Secretariat has been experimenting with inserting
"Tagged Message Delivery Agent" (TMDA) in front of Mailman lists, and
the experiment has been quite successful in reducing the number of spam
message that reach these lists.  Therefore, we would like to offer this
service to all WG chairs who are interested in taking advantage of it.

	(b) Blacklists: refusing mail from undesirable senders (i.e.,
known spammers).

	(c) Challenge/Response: allowing unknown senders who are not on
the Whitelist or Blacklist the chance to confirm that their messages are
legitimate (at which time they are added to the Whitelist).

	For IETF, the Whitelist includes every address that is
subscribed to any IETF mailing list, and the Blacklist includes any
addresses that the list administrators request be placed on them (i.e.,
because of repeated spamming).  A sender who is new to the IETF would
need to respond to the challenge only once in order to be Whitelisted.

	We plan to implement TMDA on the WG mailing lists beginning on
Monday, April 16th, and hope to complete the process in approximately
one month.  If you do *not* want TMDA inserted in front of your WG list,
then we would appreciate hearing from you by no later than Friday, April
13th.  If we do not hear from you by 5:30 ET on that date, then we will
assume that you want us to proceed.  Each list administrator will be
notified by e-mail when TMDA had been inserted in front of his or her WG
mailing list.

	Once again, this program is voluntary, so please be sure to let
us know if you wish to "opt out."

	Best Regards,

	Barbara Fuller

---

From: "Tom-PT Taylor" <[email-masked]>
Date: Tue, 10 Apr 2007 22:41:59 -0400

What is the impact on "originators" of spam who actually had their addresses 
forged as senders of the mail in question. Do they get any more messages than 
they do today?

Fuller, Barbara wrote:
> Dear IETF WG Chairs,
> 
> I am resending this message because the original one had an incorrect "Subject" line.
> 
> Barbara
> 
> -------------------------------------------------------------------------
> 
> Many of you have indicated that your WG mailing lists hosted at ietf.org receive large volumes of spam, which makes moderating the lists difficult.  The Secretariat has been experimenting with inserting "Tagged Message Delivery Agent" (TMDA) in front of Mailman lists, and the experiment has been quite successful in reducing the number of spam message that reach these lists.  Therefore, we would like to offer this service to all WG chairs who are interested in taking advantage of it.
> 
> (b) Blacklists: refusing mail from undesirable senders (i.e., known spammers).
> 
> (c) Challenge/Response: allowing unknown senders who are not on the Whitelist or Blacklist the chance to confirm that their messages are legitimate (at which time they are added to the Whitelist).
> 
> For IETF, the Whitelist includes every address that is subscribed to any IETF mailing list, and the Blacklist includes any addresses that the list administrators request be placed on them (i.e., because of repeated spamming).  A sender who is new to the IETF would need to respond to the challenge only once in order to be Whitelisted.
> 
> We plan to implement TMDA on the WG mailing lists beginning on Monday, April 16th, and hope to complete the process in approximately one month.  If you do *not* want TMDA inserted in front of your WG list, then we would appreciate hearing from you by no later than Friday, April 13th.  If we do not hear from you by 5:30 ET on that date, then we will assume that you want us to proceed.  Each list administrator will be notified by e-mail when TMDA had been inserted in front of his or her WG mailing list.
> 
> Once again, this program is voluntary, so please be sure to let us know if you wish to "opt out."
> 
> Best Regards,
> 
> Barbara Fuller
>

---

From: Lars Eggert <[email-masked]>
Date: Wed, 11 Apr 2007 10:54:48 +0300

On 2007-4-10, at 18:24, ext Henrik Levkowetz wrote:
> on the TDMA whitelist

Does "IETF list" mean "list hosted on ietf.org"? Because there are  
still some WG lists that aren't hosted there.

Lars

---

From: Henrik Levkowetz <[email-masked]>
Date: Wed, 11 Apr 2007 11:57:24 +0200

Hi Lars,

> still some WG lists that aren't hosted there.

Good point.  I suspect that you're right; Barbara's message doesn't
go into details about that, but I'd surprised if a system to continuously
feed subscriber information from externally managed lists to the
master whitelist has been set up.

Another 'it would be good to get this clarified' point.

	Henrik

---

From: <[email-masked]>
Date: Wed, 11 Apr 2007 16:07:22 -0400 (EDT)

Date: Tue, 10 Apr 2007 18:11:38 +0200
   From: "Drage, Keith \(Keith\)" <[email-masked]>
   Cc: <[email-masked]>, <[email-masked]>,         "Russ Housley" <[email-masked]>,         "Lindberg,Jon" <[email-masked]>

Currently the TMDA whitelist consists of...

  - all members of any list hosted at megatron.ietf.org which is
    @ietf.org/@iab.org/@lists.ietf.org
  - all entries in accept_these_nonmembers of all lists
  - some by-hand entries of @ietf aliases/addresses

Cheers,

sb. Scott Blomquist for [email-masked]