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RonaldVlug

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The last few months we're getting more and more spam.

How dow you guys/girls handle the spam?

Which blacklist servers do u use?

Another small question ...is there a way to let KMS scan the message body for particulair words and block them?

Many thanks for the reply's :-)

Ronald.
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niessink

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The (standard) blacklists we use are:
ORDB relays.ordb.org
Spamcop bl.spamcop.net
SpamHaus SBL-XBL sbl-xbl.spamhaus.org

About 75% of the incoming spam is directly forwarded to the "Junk E-mail" folder.

Further you can use "spam rating" to set up custom rules.




Niessink & Partners
Neede, Netherlands

[Updated on: Sun, 07 June 2009 20:27]

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figurado

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We are experiencing the same problem. The number of spam emails that are getting through Kerio's spam blocking systems has increased dramatically despite repeated efforts to improve it's reliability. In many cases vulgar spam that would seemingly be easy to block gets through. Can you provide more details on what we can do about this widespread problem?

Sjoerd you didn't answer the question about being able to block messages based on words within the body of the email but from what I can tell there is no way to do that.
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sonofcolin

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Here is a snapshot of keriomailserver stats (6.2):
Quote:


SPAM
22% - Normal message
0% - Messages marked by users as not spam
30% - Spams detected (tagged)
46% - Spams detected (rejected)
1% - Messages marked by users as spam

SMTP server statistics
Total incoming connections
21 557
Lost connections (spam repellant)
11 202
Connections rejected by blacklist
8 856
Relay attempts rejected by antispam
33
Accepted messages count
697



Spamassassin needs to 'learn' what is and isn't spam.
Careful use of blacklists and spamrepellant will reject 95+% of spam.
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freakinvibe

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We use several layers of spam protection in KMS:

1) Spam Repellent: 19 seconds

2) Public Black Lists (score +3): list.dsbl.org, dnsbl.sorbs.net, bl.spamcop.net, sbl-xbl.spamhaus.org, l1.spews.dnsbl.sorbs.net

3) Local Black Lists: IP address ranges we don't want any mail from (small list of about 10)

4) Local White Lists: Sender addresses or domains we accept all mail from (about 50, mostly newsletters)

5) Bayes: You can "tune" the .cf files if you know what you are doing

We catch 98% of Spam with this and are quite happy.

Regarding scanning the body of the mail: You could do that with a spamassassin .cf file but you really have to know the syntax. I see no simple way to do that.

Regards, Pascal

Dexion AG - The Blackberry Specialists in Switzerland
https://dexionag.ch
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niessink

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As far as I can see there is indeed no way to block messages based on words within the body of the email.

But with the options on the tab Spam Rating (Kerio Mailserver > Configuration > Content Filter > Spam Filter) you can rate messages based on words within the header of the message.

For instance, about a half year ago we were bombed with messages with email adresses with the domain fbi.gov and cia.gov. With this option you can easily reject this sort of messages.

[Updated on: Sun, 07 June 2009 20:27]

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figurado

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Thanks for the help folks. The only change I've made is adding spam repellant to the list of options that I am using. So far there does seem to be an improvement.
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RonaldVlug

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Same for me.

I activated spam repellant around 12 o'clock. Since then I havn't received any spam messages! (normaly about 20 in 6 hrs)

Don't know about the other 500 users but it worked for me ;-)

Thanks, Ronald.

[Updated on: Thu, 29 June 2006 18:31]

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scottwilkins

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Just for an added opinion and such:

I think the spam repellent is one of the best features I've seen in a very long time on spam control. Unfortunately, I also see it as one that can be broken when the senders get a clue and start allowing the wait in their sending. Overall though Kerio's spam control and abilities have so far suprized me. I can't wait for the dual level control in 6.2.0.

On a personal side, I use Yahoo's and Hotmail's and Google's e-mail services too. All three of these usually are highly rated for their spam control. Yet all three have been loosing ground to the spammers lately too. Many of the same messages getting through to our Kerio server are getting through on those services too. So, overall it's not a singled out issue with Kerio. But, rather a back and forth game where sometimes the spam blockers win, sometimes the spammer win.
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sonofcolin

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Quote:

Unfortunately, I also see it as one that can be broken when the senders get a clue and start allowing the wait in their sending


Most senders are spam bots and they already have a clue. However, the longer it takes to deliver a message the less spam it can deliver which is why the SMTP connections are dropped. Spam bots look for easy targets. It isn't looking for your mailserver in particular so it is unlikely that it would be re-programmed just to beat your smtp delay.
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sonofcolin

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The DNSBL's we use to block messages are:

cn-kr.blackholes.us
list.dsbl.org
combined.njabl.org
sbl-xbl.spamhaus.org

We add a score of 2.5 (threshold 4) to messages found in:
bl.spamcop.net

Having tested and adjusted for 2 years, this is what works well for us. Of course YMMV.
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