Mailing List Message #6909
From: Technical Support, Stalker Labs <>
Subject: Re: Spamtrap
Date: Thu, 05 Oct 2000 14:09:41 +0400
To: SIMS Discussions <>
X-Mailer: CommuniGate 3.2.2b

On Wed, Oct 4, 2000, 17:56:40 GMT
  Daniel Solomons, <> wrote:

>Hello -
>On 10/3/00 11:12 AM, "Technical Support, Stalker Labs" <>
>>> Yes - so the message is responded to as if it hit a router spamtrap?
>> Let me clarify that. Without the Unknown account any final address not found
>> locally will generate the "blah-blah user unknown" response. With the
>> routed to 'error' - "blah-blah address is blacklisted" With spamtrap the
>> spammer will get the vague "We have reasons to believe this mail is unwanted
>> here" AFTER all recipients addresses are collected (on the DATA command).
>Yes. When there are more than 3 or 10 unknowns, SIMS initiates a short or
>long delay. Other than that, the response is that of unknowns, rather than
>the unhelpful (to spammers!) spamtrap mode?
>For the long delay, at least, it might be nice to behave as if a spamtrap
>had been hit. This doesn't appear to be the case - wouldn't it be useful?

Aren't you afraid of blocking some legitimate sender - it might happen that somebody mistyped severak addresses and now you are blacklisting him?

>>> How many misses does it take? Can I set it to a lower number?
>> The parameters for suspending an SMTP session suspected in address
>> are hardcoded as follows:
>Thank you :-)
>I wonder if it makes sense to make these configurable through the
>web/communicator interface?


>>>    What if the spam is sent through a provider's smtp server that also
>>>    serves legitimate email?
>> If provider's IP is on the Clients Hosts list, it will never temp banned,
>> messages will be rejected anyway.
>I think I understand what happens, but to make sure, suppose
> is temp banned, legitimate mail from will

Those are IP addresses not domains what gets temp-banned. If both senders used the same server for sending - the message will be rejected.

>>>    Would it be helpful to also apply temporary bans on return addresses?
>> Currently temporary bans are not applied to Return-Path routing failures.
>Just a thought :-)
>>> Still, I agree it helps. Why respond to spamtraps immediately, instead of
>>> tying them up also?
>> The addresses routed to 'spamtrap' are tied till the DATA command. Tying
>> sessions longer may be not good.
>SIMS ties up sessions with unknowns and errors, why would it be more of a
>problem with spamtraps?

spamtraps should be disguised very well. I'm thinking of using random non-delivery replies in the case of spamttraps, like "Disk I/O error", "Internal routing failed", "not enough memory" - something vague and at random...

Best regards,
Dmitry Akindinov

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