Hi Matt -

I am still somewhat confused because you are painting a rather broad picture 
about your success with Alligate, and not really getting down to the nitty 
gritty specifics.  I can appreciate that you may not want to disclose your 
exact configuration.  However, I can't even figure out if all of the things 
you're talking about are available in a stock edition of Alligate with the 
MXRate subscription, or if you've extended the functionality of Alligate in 
ways that are specific to your installation, using tools or features that I 
won't have access to.

http://www.alligate.com/help/AdvGreyOptions.htm -> this seems to be the case 
specific greylisting you're talking about ...

http://www.alligate.com/help/blocking.htm -> has some tarpitting options ...

Even so, I am still pretty confused about this.  Any clarification would be 
appreciated.

Thanks!
-----
Jay Sudowski // Handy Networks LLC
Director of Technical Operations
Providing Shared, Reseller, Semi Managed and Fully Managed Windows 2003 Hosting 
Solutions
Tel: 877-70 HANDY x882 |  Fax: 888-300-2FAX
www.handynetworks.com
________________________________________
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Matt
Sent: Thursday, May 25, 2006 6:16 PM
To: [email protected]
Subject: Re: [Declude.JunkMail] Experience with 4.x

Pieced below:

Jay Sudowski - Handy Networks LLC wrote: 
I am contemplating implementing Alligate with SmarterMail in some fashion, and 
would like to pick your mind on the following:

1) SmarterMail does a great, great job at handling a huge number of SMTP 
threads so dictionary attacks are not really an issue.  We have popped up to 
2000 SMTP threads without incident.  And since addresses being attacked do not 
exist, the messages get rejected with a 550 error, connection is closed and 
there's no real strain on the server (at least in terms of I/O) -- do we get 
any benefit from putting Alligate in front of SmarterMail for dictionary attack 
prevention?
  
Definitely.  Not all dictionary attacks hit completely bad addresses, but 
detecting and stopping an should be rare if you configure it carefully.



2) Does SMTP AUTH pass-through and recipient verification actually work, all 
the time?
  
I don't use this since it is not necessary to do so for pre-scanning purposes.  
This is really designed to take the load off of a hosted mail server by 
off-loading this traffic.  I can't say personally that it works perfectly, but 
I'm sure that it does.  Other pass-through verification stuff that it does 
definitely works, and works efficiently.


3) I see greylisting as the real area that could benefit us -- we would avoid a 
lot of the zombie spam by implementing greylisting, and that would save us tons 
of resources all around.  However, I understand that some zombies are now 
greylist aware and will retry.
  
Greylisting is huge, but it has fundamental problems that kept me from using it 
in vanilla form with ORF.  I know that Nick used it with ORF and backed off.  
My big issues are two-fold.  By arbitrarily applying greylisting to everyone, 
you will effectively block E-mail from sending software that doesn't spool (and 
zombie spamware isn't the only thing with that limitation).  It's things like 
blackboxes and other forms of notification programming that lacks such 
functionality and can fail greylisting, at least for the first message.  Some 
bulk mail (ecommerce and otherwise) will only send once, or may requeue and 
send through a different IP subsequently causing delivery failures or long 
delays.  Even more important to me is the fact that greylisting causing issues 
with delaying legitimate E-mail, and I refused to implement it in ORF solely 
for this reason.  It's not acceptable for the class of service that I want to 
offer.  I want E-mail to pass through our system in less than 5 seconds except 
in extreme circumstances.

I fed Brian a framework for doing what I call "selective greylisting" which 
resolves these issues.  Essentially it only greylists when conditions warrant, 
and the only drawback is greylisting poorly configured hosts or some that leak 
spam (but not all of either).  It works so well that there is no reason to have 
it do full greylisting.  I won't go into the details of how this is done here 
because to some extent I consider it to be intellectual property.  Also note 
that Brian isn't just a coding monkey, and he contributed a lot to the end 
product and filled in many gaps.  There are also advanced tarpitting techniques 
that cause almost as many failures as greylisting does because some spamware 
detects tarpitting and disconnect, but it is variable according to when and how 
long it occurs.  The last major piece is the MXRate functionality, and it 
blocks a lot even when limited to just 100% hits (which surely aren't perfect, 
but they are very near perfect).


While I don't feel like running DLAnalyzer, we typically trend about 85% of 
email is spam that gets deleted before it's delivered, which means we probably 
had around 40,000 actual deliveries.  If we can eliminate 50% of the spam using 
MXRate and greylisting, that is a huge burden off of declude and the server in 
general.
  
I block 99.9% of all spam and our false positive rate is less than 1 in 10,000, 
with most of that being some form of advertising sent from hosts that also send 
for dirty lists, and most don't care about such things.  Most of our issues 
with personal E-mail are the result of foreign traffic, especially with China.  
Alligate certainly helps since it eliminates almost all zombies and viruses, 
but it also stops some static spammers as well, but Declude is still of course 
critical, and so is Sniffer and Eradispam, as well as some of my own 
programming.  My stats are accurate since they are based on manual review in 
repeated circumstances.  We also hold less than 1% of blocked E-mail for review 
making the task easy, and therefore false positives are more readily found.


Out of the net 288,842 messages that our gateway blocked, only 40,137 of >them 
received permanent 550 errors not related directly to bad recipients.  >All of 
the others were blocked by methods that are more passive in nature >and 
designed to exploit weaknesses of spamware.
    

Is this a reference to greylisting or some other feature in Alligate I'm not 
seeing?
  
I described the main techniques above.  It is a combination of address 
validation, tarpitting, greylisting and MXRate, but not all address validation, 
tarpitting, and greylisting is created equally.  I have never seen anyone else 
even talk about selective greylisting for instance, and I'm so damn grateful 
that I now have it.  The devil is in the details though, and even not all 
Alligate setups will achieve such results with such accuracy just like Declude 
setups.

Please also note that Brian once was bashed here for promoting his product 
while in beta, and I'm sure that I might be pissing a few off by talking about 
it, but I have tried to steer away from talk of Alligate outside of mentions 
except for where people ask since I believe it is valuable information and that 
is why we are here.  Declude could easily plug into Alligate if they wanted to 
since it supports dropping files into a directory instead of delivering them, 
and then it will pick them up when the external app is done.  I would love to 
see that happen since I only need IMail as a container for Declude.  If there 
is still a widespread adversion to this discussion, I would be happy to take it 
off-list.

Matt
---
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