Easy RBL configuration for Spamassassin?

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Level 1

115 points

Easy RBL configuration for Spamassassin?

After some searching on google and these forums, I can't seem to find a relatively simple way to enable RBL lookups in Spamassassin. I would prefer not to install the developer tools on the server or otherwise get too far away from a 'standard' server install.

I would like for Spamassassin to score my junk mail via RBL lookups rather than have them bounced immediately as we have had occasional false positives, even though we are only using sbl-xbl.

I would prefer not to do major upgrades on my server as I have a number of servers to maintain and would like a relatively simple way of rolling this 'update' out to all of my clients.

Thanks.

PowerMac G5 2.5DP Mac OS X (10.4.8)

Posted on Oct 27, 2006 2:25 PM

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Answer 1

Oct 28, 2006 5:47 AM in response to Tom Cassel

I'm not terribly comfortable with OS X Server mail, we use CommuniGate and blacklisting (cbl.abuseat.org is the most "effective" one for us).

If I haven't missed something using RBLs blocks mail from blacklisted servers, there is no scoring involved???

If you mean the mail should just be marked as **SPAM** instead of beeing blocked - maybe that's possible...

Whitelisting can also be used to permanently "unblock" domains.

I've been experimenting with getting surbl ( http://www.surbl.org/) working on OSX Server mail but I'm not sure how far I've come.

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Answer 2

Tom Cassel Author

Level 1

115 points

Oct 28, 2006 7:41 AM in response to Leif Carlsson

I am indeed trying to get an increase in Spamassassin scoring instead of having the mail bounced when flagged by an RBL.

I find the surbl.org thing interesting as well, but their website seems to suggest that you'll need to upgrade the version of Spamassassin to at least 3.1 in order for it to work reliably. This may have already answered my question on how to easily and reliably configure SA to do RBL lookups.

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Answer 3

pterobyte

Level 6

11,104 points

Oct 28, 2006 8:27 AM in response to Tom Cassel

Just to clarify and to make sure I understand your issue.

There is 2 types of smtp connections your server has to handle. One being another smtp server connecting to deliver outside mail and the other your clients using your server to deliver mail to the in- or outside.

I have yet to come across a false positive by using an RBL at the postfix level with regards to other smpt servers connecting to any of my servers.
It can however happen quite easily that a user cannot connect because currently on a blacklisted dynamic IP. I suspect the latter is your issue. This can easily be solved either by using smtp authentication and/or using an alternate submission port for our users. No need to move RBL lookups to Spamassassin for this.

Besides, the amount of marked mail you'd be letting through to your users will be enormous. Not sure they'll appreciate.

Having said that, if you must, you will need to tweak settings in /etc/amavisd.conf, install the NET::DNS perl module and add some rules.

All of this has been covered on this forum.

Let me know if you need more help.

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Answer 4

Tom Cassel Author

Level 1

115 points

Dec 11, 2006 9:58 AM in response to Tom Cassel

OK. I have figured out how to achieve what I want with minimum fuss.

1) Install xcode on server. I would have preferred to avoid this, but it gets the job done and can be uninstalled.

2) Install the module that allows network tests (sudo cpan -i Net::DNS)

3) Change the amavisd.conf file to $sa local_testsonly = 0

4) Create my own rule at /etc/mail/spamassassin to increase the value of certain RBL tests. In my case I created a text file called 80_mytweaks.cf and included lines like this to increase the scoring:

score RCVD INXBL 0 (1.5) 0 (1.5)

The entries with parenthesis around them simply add more points to an existing score applied earlier by Spamassassin.

5) Enjoy!

Hope this helps someone with similar interests.
TC

PowerMac G5 2.5DP Mac OS X (10.4.4)

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