Re: Spamassassin RBL's
On Tue, 12 Jun 2007, Reko Turja wrote: IMHO mail gateway isn't the point of checking whether machines inside are virus free or not. There should be other practises used on workstations ensuring that the inside environment is virus free at any given moment. It's impossible to guarantee that the LAN machines are virus-free at any given time, particularly if they run Windows or are portable and move in and out of the LAN. The idea of virus-checking outgoing email isn't to tell whether LAN machines are infected, but to prevent abuse of other networks and possible loss of connectivity because a virus got through the first-line defenses. -Warren Block * Rapid City, South Dakota USA ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
> IMHO mail gateway isn't the point of checking whether machines inside > are virus free or not. There should be other practises used on > workstations ensuring that the inside environment is virus free at any > given moment. There should be. But there are also users that decide to use their own XYZ anti virus because their uncle told them it is better than the one choosen by the professionals in charge of the system. That is why outgoing mail gateway is a good place to check that inside machines are not infected. I once got my email outgoing gateway inform me that some user had his machine infected, he had an antivirus, but was one week late for update... At least my outgoing mail gateway, I have control on it and the antiviruses are updated every 2 hours :) Security is better design by adding several layer of checking. At least IMHO too :) Bests, olivier ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
The directive above tells postfix to add information into headers that tell Amavis the mail was sent by someone who was authenticated by the system and thus trusted. I expect that the above mentionned headers cannot be forged. Else that would be a nice way for spam to avoid filtering. Beside, I am not sure it is a good measure to disable Amavis for any email. First goal of amavis is virus scanning, even a trusted/authenticated sender could have his machine infected and could be spreading viruses. Using the header above of course implies that the machine running postfix will relay to amavis only on loopback, not via regular IP - or using other method that can be counted as secure. And of course for viruses authenticating via SASL using encrypted authentication and real user/password pair isn't usually successful :) IMHO mail gateway isn't the point of checking whether machines inside are virus free or not. There should be other practises used on workstations ensuring that the inside environment is virus free at any given moment. -Reko ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
> The directive above tells postfix to add information into > headers that tell Amavis the mail was sent by someone who was > authenticated by the system and thus trusted. I expect that the above mentionned headers cannot be forged. Else that would be a nice way for spam to avoid filtering. Beside, I am not sure it is a good measure to disable Amavis for any email. First goal of amavis is virus scanning, even a trusted/authenticated sender could have his machine infected and could be spreading viruses. My 2 cents. Olivier ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
I see, I disabled bayes and awl in spamassassin, and updated amavisd-new from ports. I have a different problem. Mail I am sending out is being thrown away because it's being flagged as spam. I'm stumped, it never did this before. From memory, you can tell amavis which are your networks, so it doesnt scan emails on the way out. (or maybe you tell postfix to >only send the email via amavis on the way out, not in... i cant remember nor check atm). If you use SASL authentication and Postfix, you can use the following postfix directive: smtpd_sasl_authenticated_header = yes in main.cf in order to bypass the mail heading outside to be marked as spam. The directive above tells postfix to add information into headers that tell Amavis the mail was sent by someone who was authenticated by the system and thus trusted. I needed the above as the system relays mail from authenticated users from outside the netblock the server resides. In addition Amavis can read the relay_domains database created for Postfix in defining what domains are OK to send and receive mail, using for example something like: read_hash(\%local_domains, '/usr/local/etc/postfix/relay_domains'); in amavisd.conf. Hope these help you! -Reko ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
On Sun, 10 Jun 2007 12:33:00 -0700 (PDT)
Peter Pluta <[EMAIL PROTECTED]> wrote:
> I see, I disabled bayes and awl in spamassassin, and updated amavisd-new
> from ports. I have a different problem. Mail I am sending out is being
> thrown away because it's being flagged as spam. I'm stumped, it never did
> this before.
From memory, you can tell amavis which are your networks, so it doesnt scan
emails on the way out. (or maybe you tell postfix to only send the email via
amavis on the way out, not in... i cant remember nor check atm).
B
_
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deal with patients who install new versions of their own innards.
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Warned.
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Re: Spamassassin RBL's
> How can I enable spamassasssin RBL's. I'm running FreeBSD 6.1, postfix, > amavisd-new, and spamassassin with razor. I'm getting many spams that > shouldn't be getting thru with RBL's. I havent been able to find anything > useful on Google that can explain how to get RBL working with spamassassin. > Any feedback would be greatly appreciated. RDL test are enabled in SA if you configure it in the local.cf configuration. My config file is in /etc/mail/spamassassin. I can find a lines saying: skip_rbl_checks 0 rbl_timeout 30 dns_available yes that means that I use RBL, and that I wait up to 30 seconds to get an answer. I don't remember about the 3rd line, but it could be related. Reason that your RBL rules are never triggered could be that the time out is too low or that you have disabled RBL checks. Or that when you received the spam, the sender was not yet listed. But was listed lated when you did the dnsstuff.com check. If I am not confused, the list of RBL configured in SA by default is quite short, you may find it usefull to add more RBL to SA. But you are faced with the risk of adding lists that are poorly managed and have a lot of false positive. Like mentionned bellow: > Or you can out and out block servers in the RBL from your MTA. You > probably want to be carefull with the latter technique since is > transfers onus of the work of delivering the mail into the wrong > hands. If you do RBL at the MTA level, you better be sure that the RBL you use are not polluted with false positives. I'd try to run the ugly spam through SA by hand (spamassassin -t ) and see what the output is. You'll see if the RBL are triggered or not. If you are new to SA, I woudl warn you against modifying the scores for RBL, unless you no what you are doing. SA scoring is a difficulte and delicate task and modifying the scores may result in unwanted situation. Best regards, Olivier ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
Christopher Hilton wrote: > > Peter Pluta wrote: >> >> Mikhail Goriachev-2 wrote: >>> Peter Pluta wrote: How can I enable spamassasssin RBL's. I'm running FreeBSD 6.1, postfix, amavisd-new, and spamassassin with razor. I'm getting many spams that shouldn't be getting thru with RBL's. I havent been able to find anything useful on Google that can explain how to get RBL working with spamassassin. Any feedback would be greatly appreciated. >>> >>> > > [snip] > >>> /usr/local/share/spamassassin/20_dnsbl_tests.cf >>> >>> > > You will also want to look at: > > /usr/local/share/spamassassin/5-_scores.cf > > There are two ways to use the rbls. You can either raise the score for > being in the RBL above SA's threshold. Or you can out and out block > servers in the RBL from your MTA. You probably want to be carefull with > the latter technique since is transfers onus of the work of delivering > the mail into the wrong hands. > > I just spent 3 hours diagnosing a problem for a client on Friday. It > turns out that people weren't able to deliver email to him and for the > past 6 months he's believed that there was some intermittent problem > with his ISP's mailserver. The actual problem is that his ISP is using > an overzealous RBL. I found out about this because my delivery server > was listed in his RBL due to some mistake that happened in 1999 before > my ISP got the IP address. The practical upshot for my client was that > until he could find someone who could both see and diagnose the problem > he just wasn't receiving mail and thus he was loosing business. Nota > Bene for all users of RBLs. > > -- >__o "All I was doing was trying to get home from work." > _`\<,_ -Rosa Parks > ___(*)/_(*)___ > Christopher Sean Hilton > pgp key: D0957A2D/f5 30 0a e1 55 76 9b 1f 47 0b 07 e9 75 0e 14 > ___ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "[EMAIL PROTECTED]" > > I see, I disabled bayes and awl in spamassassin, and updated amavisd-new from ports. I have a different problem. Mail I am sending out is being thrown away because it's being flagged as spam. I'm stumped, it never did this before. Log entry: Jun 10 14:23:59 mail amavis[541]: (00541-04) cached f6255bb01c648fe967714d52a89e8e9c from <[EMAIL PROTECTED]> (1,0) Jun 10 14:24:00 mail amavis[541]: (00541-04) Blocked SPAM, [67.175.92.171] [67.175.92.171] <[EMAIL PROTECTED]> -> <[EMAIL PROTECTED]>, Message-ID: <[EMAIL PROTECTED] ublishing.net>, mail_id: kj76mFHOu5uA, Hits: 5.651, size: 775, 638 ms Jun 10 14:24:00 mail postfix/smtp[785]: 7A5215083F: to=<[EMAIL PROTECTED]>, relay=127.0.0.1[127.0.0.1]:10024, delay=0.84, delays=0.18/0.01/0/0.64, dsn=2.7.0, status=sent (250 2.7.0Ok, discarded, id=00541-04 - SPAM) -- View this message in context: http://www.nabble.com/Spamassassin-RBL%27s-tf3896464.html#a11051531 Sent from the freebsd-questions mailing list archive at Nabble.com. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
Peter Pluta wrote: Mikhail Goriachev-2 wrote: Peter Pluta wrote: How can I enable spamassasssin RBL's. I'm running FreeBSD 6.1, postfix, amavisd-new, and spamassassin with razor. I'm getting many spams that shouldn't be getting thru with RBL's. I havent been able to find anything useful on Google that can explain how to get RBL working with spamassassin. Any feedback would be greatly appreciated. [snip] /usr/local/share/spamassassin/20_dnsbl_tests.cf You will also want to look at: /usr/local/share/spamassassin/5-_scores.cf There are two ways to use the rbls. You can either raise the score for being in the RBL above SA's threshold. Or you can out and out block servers in the RBL from your MTA. You probably want to be carefull with the latter technique since is transfers onus of the work of delivering the mail into the wrong hands. I just spent 3 hours diagnosing a problem for a client on Friday. It turns out that people weren't able to deliver email to him and for the past 6 months he's believed that there was some intermittent problem with his ISP's mailserver. The actual problem is that his ISP is using an overzealous RBL. I found out about this because my delivery server was listed in his RBL due to some mistake that happened in 1999 before my ISP got the IP address. The practical upshot for my client was that until he could find someone who could both see and diagnose the problem he just wasn't receiving mail and thus he was loosing business. Nota Bene for all users of RBLs. -- __o "All I was doing was trying to get home from work." _`\<,_ -Rosa Parks ___(*)/_(*)___ Christopher Sean Hilton pgp key: D0957A2D/f5 30 0a e1 55 76 9b 1f 47 0b 07 e9 75 0e 14 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
Mikhail Goriachev-2 wrote: > > Peter Pluta wrote: >> How can I enable spamassasssin RBL's. I'm running FreeBSD 6.1, postfix, >> amavisd-new, and spamassassin with razor. I'm getting many spams that >> shouldn't be getting thru with RBL's. I havent been able to find anything >> useful on Google that can explain how to get RBL working with >> spamassassin. >> Any feedback would be greatly appreciated. > > > RBL is already enabled in SA. Probably you should increase the values SA > assigns to RBL checks. See: > > http://www.spamhaus.org/effective_filtering.html > > Skim through: > > /usr/local/share/spamassassin/20_dnsbl_tests.cf > > > Just a thought. You may consider implementing RBL at MTA level (postfix > in your case). It is a lot faster then processing through SA, which is a > resource hog. > > > > Regards, > Mikhail. > > -- > Mikhail Goriachev > Webanoide > > Telephone: +61 (0)3 62252501 > Mobile Phone: +61 (0)4 38255158 > E-Mail: [EMAIL PROTECTED] > Web: www.webanoide.org > ___ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "[EMAIL PROTECTED]" > > Thanks, I think postfix already does the basic RBl's. PTR records and stuff like that, but i'm still getting some ugly spam. When I feed the spam ip's into dnsstuff.com's spam database many of the databases show it as blacklisted, so i'm guessing the RBL's are not functioning correctly. -- View this message in context: http://www.nabble.com/Spamassassin-RBL%27s-tf3896464.html#a11050907 Sent from the freebsd-questions mailing list archive at Nabble.com. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Spamassassin RBL's
Peter Pluta wrote: How can I enable spamassasssin RBL's. I'm running FreeBSD 6.1, postfix, amavisd-new, and spamassassin with razor. I'm getting many spams that shouldn't be getting thru with RBL's. I havent been able to find anything useful on Google that can explain how to get RBL working with spamassassin. Any feedback would be greatly appreciated. RBL is already enabled in SA. Probably you should increase the values SA assigns to RBL checks. See: http://www.spamhaus.org/effective_filtering.html Skim through: /usr/local/share/spamassassin/20_dnsbl_tests.cf Just a thought. You may consider implementing RBL at MTA level (postfix in your case). It is a lot faster then processing through SA, which is a resource hog. Regards, Mikhail. -- Mikhail Goriachev Webanoide Telephone: +61 (0)3 62252501 Mobile Phone: +61 (0)4 38255158 E-Mail: [EMAIL PROTECTED] Web: www.webanoide.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Spamassassin RBL's
How can I enable spamassasssin RBL's. I'm running FreeBSD 6.1, postfix, amavisd-new, and spamassassin with razor. I'm getting many spams that shouldn't be getting thru with RBL's. I havent been able to find anything useful on Google that can explain how to get RBL working with spamassassin. Any feedback would be greatly appreciated. -- View this message in context: http://www.nabble.com/Spamassassin-RBL%27s-tf3896464.html#a11046174 Sent from the freebsd-questions mailing list archive at Nabble.com. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
