In today's world, spam continues to run amok, and becoming a serious problem, because spammers have become more and more intelligent, so to prevent spam on any person running a mail server is a very necessary things.
For Linux, now there is a remarkable tool for preventing spam: SpamAssasin. Now we'll look at how SpamAssasin curb spam. Understanding SpamAssassinSpamAssasin is a mail filtering device, it can use a series of mechanisms to identify spam, these mechanisms include: text analysis, and Bayesian (Bayes rule) worry, DNS block lists, as well as collaborative filtering database. SpamAssasin and cannot delete spam, it can block spam. The reasons were mainly lies in the fact that it has the following characteristics: wide range of activities: SpamAssasin uses a wide range of both local and network tests to identify spam characteristics. This allows spammers to clear its manufacturing of informationnatural hair loss products work of increasing the difficulty. Free software: and other popular open source software (such as ApacheWebServer), under the same conditions. Easy to scale: anti-spam test and configuration information is stored in plain text, which makes configuration and adding new rules is fairly easy. Flexibility: SpamAssasin to logic encapsulated in a well-designed, abstract API so it can be integrated into email anywhere in the data stream. SpamAssasin can be used for a variety of email systems including procmail, sendmail, Postfix, qmail, and so on. Easy configuration: SpamAssasin almost no user configuration. You don't have to use a mail account or mailing list membership details to continually update configure SpamAssasin. Once classified, site and user rules can be used in spam. And rules can be applied to the message server, and later you can use the user's own mail user-agent application. SpamAssasin is generally considered the best spam filter. This article will guide you through the process of installing, configuring, and using this powerful tool. Obtaining and installing SpamAssasin as a Linux application, there are various methods for installing SpamAssasin. The following is a list of simple installation method: Debianunstable: apt-getinstallspamassassinGentoo: emergemail-filter/spamassassinFedora: yuminstallspamassassin users available from SpamAssasin (http://spamassassin.apache.org/downloads.cgi?update=200702131100) download related documents. File ready, in the console prompt, enter the following command: untar/unziptheilecdintothenewlycreateddirectoryperlMakefile.PLOPTION: Add-DSPAMC_SSLto $ CFLAGStobuildanSSL-enabledspamc] makemakeinstall [asroot] in the INSTALL file in a significant number of specific publishing rules and secondary rules. So you want to install before you complete reading this file. As the system-wide use for installation as a system-wide for use with the installation of one of the best reason is that you don't have to change a user's procmailrc file. This can be a headache, this depends on your number of users. Since this procedure will theoretically disrupt users ' e-mail, put it in a pilot environment running tests is very wise. Configuration just like most Linux applications, SpamAssasin need to edit the configuration file. This configuration file is located in the local.cf/etc/mail/spamassassin/. When you manually edit the configuration file, you can note it, has written a MichaelMoncur excellent tool SpamAssassinConfigurationGenerator, it helps users create local.cf file. However, the tools are currently only works in SpamAssasin3.x. This tool provides a Web-based suite of options, you can help users to create their own configuration file. In the select Mr.Moncur created simple option is selected, press the "Generate": # Generatedbyhttp://www.yrex.com/spam/spamconfig.php (version1.50) # Howmanyhitsbeforeamessageisconsideredspam.required_score7.5 # Changethesubjectofsuspectedspamrewrite_headersubject ***** SPAM ***** # Encapsulatespaminanattachment (0 = no, 1 = yes; 2 = sae) report_sae1 # EnabletheBayessystemuse_bayes1 # EnableBayesauto-learniNgbayes_auto_learn1 # Enableordisablenetworkcecksskip_rbl_checks0use_razor21use_dcc1use_pyzor1 # Mailusinglanguagesusedinthesecountrycodeswillnotbemarked # asbeingpossiblyspaminaforeignlanguage.ok_languagesall # Mailusinglocalesusedinthesecountrycodeswillnotbemarked # asbeingpossiblyspaminaforeignlanguage.ok_localesall below we analyse: ScoreThreshold (evaluation limits): the lower the threshold value, there would be fewer messages through. The default value is 6. But you have to note: If you set this setting is too low, a number of legitimate e-mail messages will be treated as spam blocked. RewriteMessageSubjects (rewrite message topic): with this option, you can configure SpamAssassin with your choice of any object to edit the subject line of the e-mail message. The default value is set to: * * *** SPAM *** ** UseAutoLearning (with automatic learning): SpamAssassin can be through the analysis of certain evaluation of message, go to organize its automation Bayes (Bayesian) database, this evaluation strongly shows the message is spam or not spam messages. EnableRBLChecks (enable RBL check): Select whether you should use the SpamAssassin RBLS (DNS blacklist). This helps to detect hard to detect spam, but need to consume some time and network bandwidth, and a DNS server is available. UseNetworkChecksumTests (using network check and testing): Select whether to use the message check and (Checksum) and known spam comparison services: these services are: Vipul'sRazor2.x, DCC, Pyzor, etc., but only when each client software install these services to work properly. (I.e., through use_razor2, use_dcc use_pyzor). Languages (language): the last two configuration is about language, the first is what language should check. The default options for all languages. The author recommends that you do not modify. If you use Mr.Moncur application creation your .cf file, store it in a/etc/mail/spamassassin/, and then start the spamassassin application. If you want to run spamassassin, you must run as root the following commands:/etc/rc.d/init.d/spamassassinstart Note: depending on your release version, spamassassin can be located in/etc/init.d/. Up and running spamassassin, you can expect at each startup, the program will start running. You can use system-config-services this application, or check the Enable spamassassin options. If the user does not have this software, you can system-config-services in/etc/rc.local file increase as follows:/etc/rc.d/init.d/spamassassinstart or/etc/init.d/spamassassinstart depending on what you can do the SpamAssassin. And Procmail to work your spamassassin is already up and running, now requires you to set it and the message transfer agent (MailDeliveryAgent) work together. In this I assume you are using procmail, as it is in a Linux environment, the most widely used mail transfer agent. Users need to edit the file and add the following/etc/procmailrc: DROPPRIVS = yes: 0w |/usr/bin/spamc now procmail is set to use SpamAssassin to filter into the evaluation and the spam. Spam blacklist we know some domain/user sends spam. Fortunately, SpamAssassin has a deal with known spammers. With the help of the blacklist, SpamAssassin and toward the best and last spam defense and a step. Set up a blacklist is a very simple matter. You can add two configuration files. For site-wide use, consider/etc/mail/spamassain/local.cf; ~/.spamassassin/user_prefs, each user can configure their own blacklist. Blacklist looks as follows: blacklist_from & nbspsample_email@sampledomain.com blacklist_from@sampledomain.com blacklist_from@sampledomain.com blacklist_from@sampledomain.com above content quite clearly shows us how to mixReset the blacklist. That is, you can configure a specific e-mail address (? A HREF = "mailto: sample_email@sampledomain.com), you can also configure an entire domain (such as * @ sampledomain.com)" > sample_email@sampledomain.com), you can also configure an entire domain (such as * @ sampledomain.com) If you don't want to spend hours editing your own blacklist, you can download the latest from http://www.sa-blacklist.stearns.org/sa-blacklist/sa-blacklist.current's blacklist. However, may not be suitable for your needs, there are many Chinese spam sites and are not included. But this list is enormous, so download this list and add to your blacklist to be careful. Training your SpamAssassin likely your SpamAssassin does not properly evaluate email is spam. If this happens, you can use your own e-mail training SpamAssassin. To do this, you need to use an SSH program (such as SSH or Putty, etc.) and SpamAssassin'ssa-learn program. The mail server, you must also set the IMAP protocol for training SpamAssassin. To training SpamAssassin, users should follow the following steps: 1. spam mail from working properly separating, placed in a separate mailbox. 2. open a ssh application and connect to jupiter.gac.edu. 3. run the following two commands: sa-learn--ham--progress--mboxMail/nameOfYourHamMailboxsa-learn--spam--progress--mboxMail/nameOfYourSpamMailbox if you use more than 200 spam and 200 OK message to training your SpamAssassin, it will use this information to determine what is spam and what is not. Closing the author believes SpamAssassin can block spam spread of one of the necessary tool. It can be said, in a corporate environment running a mail server, but if you do not have to take any preventive measures, let spam through your transmission channel indiscriminately spread, it's a nightmare. Imagine setting prevents spam software, the importance of the simplicity of the SpamAssassin to use it, do you have any reason not in your Linux mail server deployment SpamAssassin the good stuff, maybe your mail server or your WEB services will increase in popularity.
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