Alexander Bochmann writes on 12/2/2003 2:05 PM:
If some of the large Email providers like Outblaze,
Hotmail, Yahoo, AOL, etc. could agree on a more
integrated approach to implement at least some form
of sender authorization - possibly in the line of the
RMX RR draft[1] - as a service to the p
On Tue, 02 Dec 2003 20:05:47 +0100, Alexander Bochmann <[EMAIL PROTECTED]> said:
> I agree that much of the anti-spam stuff out there
> is kludgy at best, and often harmful to other users,
> but let's not forget that it's the spammers who make
> all this necessary...
Today's stupid spammer t
Hi,
...on Tue, Dec 02, 2003 at 07:23:41PM +0800, Suresh Ramasubramanian wrote:
> What they are trying to do is to connect back
> to email.com's MXs and ensure that the user
> <[EMAIL PROTECTED]> who is trying to
> send them mail really does exist, [..]
> It does tend to cut down on the a
(susan, this is in a spam related thread but i'm adding offtopic remarks
which i think are actually in-charter for nanog. --pv)
> Verizon does SMTP callbacks, connecting back to the MX of the envelope
> sender and trying to verify that the user exists
while something like RMX or MAILFROM would p
> Exactly this is the flawed point about returning 4xx. They produce
> only collateral damage, but don't hit their target at all.
but they can feel self-righteous, which is probably the major goal
> telling spammers 4xx or 5xx doesn't matter, they don't listen.
yes, but interestingly, every "smtp transport" (remote ip address who
connects to your tcp/25 service) who ignores 5XX (which you can tell
because they come back and try the same thing again over and over) is
either a spammer or the
Richard Cox writes on 12/2/2003 9:57 AM:
VRFY is an (unavoidable) part of the checking routine built into the
popular "Sam Spade for Windows" client, for manual verification of any
suspect addresses found to have sent suspicious mail. So just looking
for VRFY can give you some, er, false positiv
On Tue, 02 Dec 2003 14:37 UTC Suresh Ramasubramanian
<[EMAIL PROTECTED]> wrote:
| Nobody except spammers / dictionary attackers seem to VRFY these days
| for this sort of stuff. In fact grepping your logs for VRFY is often
| a reliable sign of a dictionary attack on your machines.
VRFY is an (u
[EMAIL PROTECTED] writes on 12/2/2003 9:32 AM:
On Tue, 02 Dec 2003 19:23:41 +0800, Suresh Ramasubramanian <[EMAIL PROTECTED]> said:
What they are trying to do is to connect back to email.com's MXs and ensure
that the user <[EMAIL PROTECTED]> who is trying to send them mail
really does exist, an
On Tue, 02 Dec 2003 19:23:41 +0800, Suresh Ramasubramanian <[EMAIL PROTECTED]> said:
> What they are trying to do is to connect back to email.com's MXs and ensure
> that the user <[EMAIL PROTECTED]> who is trying to send them mail
> really does exist, and is not just a figment of some spambot's i
On Tue, Dec 02, 2003 at 03:37:00AM -0700, John Brown (CV) wrote:
> telling spammers 4xx or 5xx doesn't matter, they don't listen.
Exactly this is the flawed point about returning 4xx. They produce
only collateral damage, but don't hit their target at all.
Regards,
Daniel
[EMAIL PROTECTED] wrote:
> Why on earth would Verizon need to do the lookup once per
> incoming email? If they need to verify that a given MX
> does indeed exist and is reachable and is running an
> SMTP server, then why not cache that info for some
Er.. they are not looking for "MX exists". If
" John Brown (CV)" <[EMAIL PROTECTED]> wrote:
> telling spammers 4xx or 5xx doesn't matter, they don't listen.
The goal is to keep your spool clear, and your mailservers operational.
At least, that is, if you are running a production server and not a hobbyist / family
and friends type setup.
telling spammers 4xx or 5xx doesn't matter, they don't listen.
On Mon, Dec 01, 2003 at 09:18:21PM +0100, Daniel Roesen wrote:
>
> On Mon, Dec 01, 2003 at 12:52:28PM -0700, Michael Lewinski wrote:
> > The idea is to "punish" spammers by filling up their queues, although
> > honestly I don't know
>Also imagine your domain being joe-jobbed. You, as an innocent
bystander,
>then get hammered by Verizon as they try to do a lookup on possibly
>millions of incoming mails.
Why on earth would Verizon need to do the lookup once per
incoming email? If they need to verify that a given MX
does inde
On Mon, 1 Dec 2003, Steven M. Bellovin wrote:
> Right. Assuming that the described validation scheme is, in fact,
> what's being used, you'd expect Verizon's mailer to retain and cache
> the validation. That way, a single 450 can be turned into a 200 series
> or a 550.
Also imagine your domain
jared:
this is the ability of a single host operator to make
their own local policy decisions.
randy:
>>> which leads to the heat death of the net
joe:
>> or allows the net to prosper, since policy is distributed rather than
>> centralised.
randy:
> consider verifying, or making any ass
On Mon, Dec 01, 2003 at 12:52:28PM -0700, Michael Lewinski wrote:
> The idea is to "punish" spammers by filling up their queues, although
> honestly I don't know of any spammers who actually *have* queues. They
> just borrow other people's of course.
Correct. More and more, anti-spammers are an
On Mon, 01 Dec 2003 14:51:01 EST, Joe Abley said:
> or allows the net to prosper, since policy is distributed rather than
> centralised.
Tell anybody who suffered through 69/8 how that was an example of the net prospering.
pgp0.pgp
Description: PGP signature
>>> this is the ability of a single host operator to make
>>> their own local policy decisions.
>> which leads to the heat death of the net
> or allows the net to prosper, since policy is distributed rather
> than centralised.
consider verifying, or making any assertions about, or having any
conf
On Dec 1, 2003, at 11:10 AM, Randy Bush wrote:
is the following a general problem, or just one i am seeing?
note 2821 says
450 Requested mail action not taken: mailbox unavailable
(e.g., mailbox busy)
550 Requested action not taken: mailbox unavailable
(e.g., mailbo
On 1 Dec 2003, at 14:29, Randy Bush wrote:
this is the ability of a single host operator to make
their own local policy decisions.
which leads to the heat death of the net
or allows the net to prosper, since policy is distributed rather than
centralised.
In message <[EMAIL PROTECTED]>, Michael Loft
is writes:
>
>I personally haven't seen ANY validation, just an arbitrary block that's
>been in place for over a month without cause, reason, or even any ability
>to contact them.
Right. Assuming that the described validation scheme is, in fact,
w
> this is the ability of a single host operator to make
> their own local policy decisions.
which leads to the heat death of the net
randy
I personally haven't seen ANY validation, just an arbitrary block that's
been in place for over a month without cause, reason, or even any ability
to contact them. It appears nobody at verizon is at the helm anymore.
I've tried several times to contact abuse, postmaster, etc, and even a
couple
On Mon, Dec 01, 2003 at 11:10:16AM -0800, Randy Bush wrote:
> > I think he's saying that they were unable to perform the
> > validation hence the 450. If the validation was successful,
> > they'd return a 200 series code, if it was unsuccessful, they
> > would return a 500 series code.
>
> nice
> I think he's saying that they were unable to perform the
> validation hence the 450. If the validation was successful,
> they'd return a 200 series code, if it was unsuccessful, they
> would return a 500 series code.
nice words, but crap. due to needs to spool mail for sites in
countries with
On Mon, Dec 01, 2003 at 10:50:51AM -0800, Randy Bush wrote:
>
> >> is the following a general problem, or just one i am seeing?
> >
> > Verizon does SMTP callbacks, connecting back to the MX of the envelope
> > sender and trying to verify that the user exists
> >
> >>
> >> 2003-12-01 10:09:05
Randy Bush writes on 12/1/2003 1:50 PM:
interesting but utterly irrelevant. the question was not how
verison decided it was spam. the point was that their server
returned a 450 as opposed to a 5xx (550 looks good), and this
causes net damage.
They haven't yet determined that it is spam. So, RF
Neezam Haniff writes on 12/1/2003 1:46 PM:
On Mon, 1 Dec 2003, Suresh Ramasubramanian wrote:
So this would connect to the MX of gerbangmail.com and try to verify
that [EMAIL PROTECTED] exists.
Out of curiosity, would you know offhand how they do the
validation?
It is my job to know, I guess .
>> is the following a general problem, or just one i am seeing?
>
> Verizon does SMTP callbacks, connecting back to the MX of the envelope
> sender and trying to verify that the user exists
>
>>
>> 2003-12-01 10:09:05 1APbBa-000Ork-DY == [EMAIL PROTECTED] <[EMAIL PROTECTED]>
>> R=lookuphost T
On Mon, 1 Dec 2003, Suresh Ramasubramanian wrote:
> So this would connect to the MX of gerbangmail.com and try to verify
> that [EMAIL PROTECTED] exists.
Out of curiosity, would you know offhand how they do the
validation?
Neezam.
I think you will find that people who want to reject the spam
but don't want to accidentally reject real mail will sometimes
use 45x instead of 55x error codes.
I know when i was rejecting spam at the SMTP layer
I first started rejecting with 45x and watched my logs
for those pesk
Randy Bush writes on 12/1/2003 1:10 PM:
is the following a general problem, or just one i am seeing?
Verizon does SMTP callbacks, connecting back to the MX of the envelope
sender and trying to verify that the user exists
2003-12-01 10:09:05 1APbBa-000Ork-DY == [EMAIL PROTECTED] <[EMAIL PROTECTE
is the following a general problem, or just one i am seeing?
note 2821 says
450 Requested mail action not taken: mailbox unavailable
(e.g., mailbox busy)
550 Requested action not taken: mailbox unavailable
(e.g., mailbox not found, no access, or command rejected
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