kirdy stevens movies 3d card download video site jetski freestyle videos london drug photo finishing inhouse drug store scam sex drugs evasive angles video europa jupiter mission neuroleptic drugs definition salaries james madison university advertising in movie theatres american college of pharmacy education bellagio italy adderall sleepy url shakira clip de video winx club naked indiana home loan new tagalog movies lauren mai watchersweb com galleries kayak video piss slide video car valet services leadership training in las vegas movie tickets coupons hawaiian tours terminos poeticos keine lust video download rammstein kid fun sites sand art projects genital warts pictures 1by1 mp3 player adobe after effects videos cheap phentermine and adipex without perscription itunes movies world class gymnastics illinois license key diner dash links skate boarding video clip elizabeth montgomery massive attack music video audio converter serial xilisoft italian carmaker mommy dearest movie push pins sell your video games muvico movie theater crooked tongues webmap scary movie 3 soundtrack pacific care auto loan calculator gold digger ringtone santorini greece mexican movies for sale sports stadium wav free ringtone verizon vx3300 lol funny erica campbell free movie seattle seafair pirates qimage pro crack the fifth element michigan drivers license points amtrak crash video all 4 one i swear video sitemap continuous emissions monitoring system mp3 dancer crack music video coeds aurora fox mall valley rows to columns elephant movie posters music video auditions fun underwear terrence howard pictures ge medical equipment chiropractors movie extras for kid nudegirls washington state university online degrees make your own wedding favor ideas easy video joiner download site spencer tracey movies mount olive nj summer camp patricia ford movies south central college mankato mount holyoke college massachusetts hair straightener writing proposal category polyphonic ringtone horse suck free nextel 860 ringtone institutional investor contacts liger video nbc oozaru images element fifth movie kawai piano serial [http://s1.shard.jp/frhorton/t45lfscw6.html vegetation zones in africa ] top [http://s1.shard.jp/olharder/44-auto-trader-nz.html autosomal recessive pedigree chart ] [http://s1.shard.jp/frhorton/rykfyeh82.html african catfish breeding ] [http://s1.shard.jp/olharder/stan-olsen-auto.html pip auto ] [http://s1.shard.jp/frhorton/ru9zwzdr5.html african american body builders ] [http://s1.shard.jp/olharder/general-motor.html auto differential ] [http://s1.shard.jp/galeach/new188.html asian tigers countries ] [http://s1.shard.jp/frhorton/j1znr5lny.html africa east news ugandas ] [http://s1.shard.jp/bireba/disable-norton.html norton antivirus key code ] [http://s1.shard.jp/galeach/new86.html myelodysplasia leukemia ] map [http://s1.shard.jp/galeach/new108.html gay asian pic ] [http://s1.shard.jp/galeach/new183.html asian groove.com ] [http://s1.shard.jp/olharder/canadian-auto.html how to automate ftp ] [http://s1.shard.jp/bireba/nod-antivirus.html antivirus checkup ] [http://s1.shard.jp/frhorton/yoc3js17e.html scramble for africa germany ] [http://s1.shard.jp/olharder/removing-auto-paint.html nikon auto level ap 3 ] [http://s1.shard.jp/bireba/avg-antivirus-7.html crack for avg antivirus 7.1 ] [http://s1.shard.jp/frhorton/c769e8i7o.html 19th century african american poets ] [http://s1.shard.jp/galeach/new111.html asian black hardcore ] [http://s1.shard.jp/frhorton/4bgszojmg.html hair style for african kid ] [http://s1.shard.jp/losaul/i-still-call-australia.html isp australia ] physiotherapy colleges in australia [http://s1.shard.jp/olharder/auto-club-country.html economy auto mart ] [http://s1.shard.jp/frhorton/zedmbj3he.html 5th test south africa ] [http://s1.shard.jp/losaul/mark-edmondson-australian.html digital tv forum australia ] [http://s1.shard.jp/galeach/new105.html asian skewered dish ] [http://s1.shard.jp/frhorton/o5mgjok5p.html south africa car rentals ] [http://s1.shard.jp/bireba/download-free.html uninstall norton antivirus corporate ] [http://s1.shard.jp/galeach/new27.html asian anorexic ] [http://s1.shard.jp/galeach/new146.html religious map of southwest asia ] [http://s1.shard.jp/frhorton/p7w3g6anv.html travel agency africa singapore ] http [http://s1.shard.jp/frhorton/3otvgvzdn.html africas land ] asian art museum [http://s1.shard.jp/bireba/norton-antivirus.html antivirus for exchange servers ] http [http://s1.shard.jp/frhorton/9df15nbui.html african american car driver race ] [http://s1.shard.jp/olharder/art-auto-ltd.html capital one autofinance ] [http://s1.shard.jp/losaul/new-england-university.html model boats australia ] [http://s1.shard.jp/galeach/new128.html acetabular developmental dysplasia dysplasia hip ] index [http://s1.shard.jp/olharder/auto-insurance.html autograph club collector universal ] [http://s1.shard.jp/frhorton/64klk5ggy.html african american author by short story ] [http://s1.shard.jp/bireba/avg-antivirus-73.html avg antivirus 6.0 ] [http://s1.shard.jp/olharder/automation-building.html maple story auto loot ] [http://s1.shard.jp/losaul/australia-transcriber.html good food guide melbourne australia ] [http://s1.shard.jp/frhorton/h9wk8xs2j.html africa development government in local role south ] [http://s1.shard.jp/frhorton/ns971gffq.html history of corruption in africa ] [http://s1.shard.jp/galeach/new194.html humane society euthanasia statistics ] [http://s1.shard.jp/losaul/little-tykes-toys.html topo maps australia online ] [http://s1.shard.jp/olharder/auto-bill-fitts.html autographed ball golf ] site map [http://s1.shard.jp/frhorton/wntjtqor2.html early south african music ] [http://s1.shard.jp/losaul/australian-cricket.html the biggest loser australia ] links [http://s1.shard.jp/losaul/wiremesh-australia.html gove australia ] [http://s1.shard.jp/olharder/autobiographer.html automatic vents ] [http://s1.shard.jp/losaul/scoutsaustralia.html jal airline australia ] [http://s1.shard.jp/galeach/new141.html anastasia beverly hills ca ] [http://s1.shard.jp/bireba/latest-antivirus.html avg antivirus key generator ] [http://s1.shard.jp/bireba/notron-antivirus.html rav antivirus updates ] [http://s1.shard.jp/bireba/top-ten-antivirus.html grisoft antivirus ] [http://s1.shard.jp/losaul/moosehead-beer.html shogun bicycles australia ] [http://s1.shard.jp/bireba/antivirus-avg7.html vista antivirus ] [http://s1.shard.jp/frhorton/iyc9ldho5.html recent inventions by african americans ] [http://s1.shard.jp/bireba/norton-antivirus.html antivirus filtering ] [http://s1.shard.jp/losaul/australia-immigration.html unskilled jobs in australia ] [http://s1.shard.jp/olharder/baltimore-auto.html aa12 automatic military shotgun ] [http://s1.shard.jp/bireba/download-kaspersky.html antivirus free download software ] [http://s1.shard.jp/olharder/invicta-speedway.html royal auto sales inc ] [http://s1.shard.jp/bireba/avast-antivirus.html norton antivirus free download full version ] [http://s1.shard.jp/bireba/clam-win-antivirus.html giant antivirus software ] [http://s1.shard.jp/bireba/norton-antivirus.html crack of norton antivirus 2005 version ] [http://s1.shard.jp/olharder/prestige-auto.html autobiography of bruce lansky ] [http://s1.shard.jp/frhorton/k7b9qt4bf.html longitude and lattitude of south africa ] [http://s1.shard.jp/bireba/antivirus-comparison.html panda software antivirus ] [http://s1.shard.jp/bireba/how-to-activate.html macffe antivirus ] [http://s1.shard.jp/galeach/new38.html southeast asian tsunamis ] [http://s1.shard.jp/olharder/automobile-promotion.html impact of automobile in the 1920s ] [http://s1.shard.jp/bireba/download-free.html avg antivirus professional crack ] [http://s1.shard.jp/frhorton/jxumdkxje.html african american christian org ] [http://s1.shard.jp/olharder/wheels-and-deals.html classic automotive group ] [http://s1.shard.jp/galeach/new5.html anastasia mp3 downloads ] [http://s1.shard.jp/galeach/new157.html clediocranial dysplasia ] [http://s1.shard.jp/bireba/northon-antivirus.html nortun antivirus ] [http://s1.shard.jp/losaul/australian-gold.html house garden australia ] [http://s1.shard.jp/galeach/new143.html anastasias closet ] art auto ltd vintage [http://s1.shard.jp/galeach/new13.html mall of asia philippines ] [http://s1.shard.jp/frhorton/9ilzodadz.html solidarity union south africa ] [http://s1.shard.jp/losaul/australian-landscape.html australian surfer boys ] [http://s1.shard.jp/bireba/antivirus-trials.html installing antivirus software ] links [http://s1.shard.jp/olharder/aa-auto-route-planner.html instacreditautomart ] vet antivirus [http://s1.shard.jp/bireba/linux-antivirus.html softwares antivirus ] [http://s1.shard.jp/olharder/hertz-autovermietung.html autocad readers ] [http://s1.shard.jp/frhorton/ocdp2flvo.html african american independent film ] [http://s1.shard.jp/losaul/little-tykes-toys.html australia estate melbourne real victoria ] [http://s1.shard.jp/galeach/new2.html asian babe pictures ] [http://s1.shard.jp/galeach/new70.html asia carrera mpeg ] [http://s1.shard.jp/losaul/centacare-australia.html goninan australia ] [http://s1.shard.jp/frhorton/a8agxerme.html south africa afrikaans ] [http://s1.shard.jp/olharder/auto-vaccom.html autobiography child ] [http://s1.shard.jp/bireba/norton-antivirus.html house call antivirus free ] [http://s1.shard.jp/bireba/antivirus-appliance.html house call antivirus free ] top http sitemap [http://s1.shard.jp/frhorton/1kjwm4ocq.html south africa vacation rental ] [http://s1.shard.jp/olharder/wes-finch-auto-plaza.html voyage en autocar ] symantec antivirus licenses [http://s1.shard.jp/frhorton/kvvijfhfe.html african rain forest food chain ] [http://s1.shard.jp/bireba/avg-antivirus-7.html pc magazine antivirus ratings ] [http://s1.shard.jp/losaul/china-export-to.html internet names australia ] [http://s1.shard.jp/galeach/map.html hamamoto asian ] [http://s1.shard.jp/frhorton/c1k98s3rt.html kampala uganda africa ] [http://s1.shard.jp/frhorton/c769e8i7o.html african lion safari hamilton ] [http://s1.shard.jp/olharder/jl-french-automotive.html tools for auto body ] [http://s1.shard.jp/frhorton/u91w9mfua.html largest crocodile in africa ] [http://s1.shard.jp/olharder/auto-ventashade.html c g automation ] [http://s1.shard.jp/galeach/new1.html asia charter luxury yacht ] [http://s1.shard.jp/frhorton/77iqsoujy.html south african dancers ] [http://s1.shard.jp/losaul/open-source-software.html shipping lines australia ] [http://s1.shard.jp/galeach/new9.html asian buddy icons for aim ] [http://s1.shard.jp/frhorton/zedmbj3he.html knysna quays hotel south africa ] [http://s1.shard.jp/frhorton/tnw2399fu.html primitive african tribes ] [http://s1.shard.jp/frhorton/l648khtsn.html south african lotto fraud ] [http://s1.shard.jp/losaul/desert-map-of-australia.html medical specialists australia ] auto hydrogene african art london [http://s1.shard.jp/losaul/emmigrating-australia.html uk pounds to australian dollars ] [http://s1.shard.jp/galeach/new36.html young petite asian teen ] site australia inc lottery lotto programme [http://s1.shard.jp/olharder/subasta-de-autos.html literary autobiography 1994 infant prodigy ] [http://s1.shard.jp/galeach/new187.html rfid world asia 2005 ] [http://s1.shard.jp/galeach/new37.html cute little asian girls ] [http://s1.shard.jp/olharder/aa-auto-route-planner.html discount auto parts jacksonville ] [http://s1.shard.jp/bireba/avg-antivirus-software.html etrust antivirus 7.1 retail ] [http://s1.shard.jp/olharder/discount-import.html semi automatic weapons definition ] [http://s1.shard.jp/frhorton/ndbzagarh.html african furniture inspired ] [http://s1.shard.jp/olharder/concession-auto.html autopsy doctors ] [http://s1.shard.jp/galeach/new100.html anastasia nikolaevna romanov ] person search in south africa [http://s1.shard.jp/losaul/limousine-hire.html online toy shop australia ] [http://s1.shard.jp/losaul/australian-momentum.html gin gin western australia ] [http://s1.shard.jp/galeach/new123.html joblink asia ] [http://s1.shard.jp/galeach/new14.html asian massage nj ] sitemap links sinful asian [http://s1.shard.jp/losaul/australia-physiotherapy.html rent a wreck australia ] [http://s1.shard.jp/frhorton/rkgv2463v.html albino african clawed ] [http://s1.shard.jp/galeach/new103.html volentary euthanasia ] [http://s1.shard.jp/bireba/avg-free-antivirus.html dansguardian antivirus ] [http://s1.shard.jp/bireba/avg-antivirus.html aol mcafee antivirus ] [http://s1.shard.jp/frhorton/vuku1m6uz.html african volcanoe ] [http://s1.shard.jp/losaul/bank-of-ireland.html digital set top box australia ] [http://s1.shard.jp/bireba/antivirus-2004.html symantech antivirus updates ] [http://s1.shard.jp/bireba/symantec-antivirus.html online scan antivirus ] [http://s1.shard.jp/olharder/tactical-automated.html shipping boxes for auto glass ] [http://s1.shard.jp/bireba/install-software.html 64 bit antivirus software ] page [http://s1.shard.jp/olharder/yesterdays-auto.html 2006 auto saloon tokyo ] [http://s1.shard.jp/losaul/job-search-cairns.html genes reunited australia ] [http://s1.shard.jp/losaul/bmw-australia.html the australian immigration ] [http://s1.shard.jp/frhorton/bc7zse5ug.html africa move ] map sitemap [http://s1.shard.jp/galeach/new139.html asiansky shop ] houston tx asian massage [http://s1.shard.jp/losaul/australia-stables.html australia tickets ] [http://s1.shard.jp/galeach/new30.html university south asia ] [http://s1.shard.jp/olharder/auto-emissions-test.html auto body shop in seattle ] [http://s1.shard.jp/olharder/automotive-training.html columbia auto insurance ] [http://s1.shard.jp/frhorton/91rryr9x4.html northern africa ] [http://s1.shard.jp/losaul/job-agencies-sydney.html retrovision australia ] download free norton antivirus2004 how to repot african violets [http://s1.shard.jp/frhorton/smui5er3r.html hivaids in african americans ] map [http://s1.shard.jp/losaul/australian-sports.html australia big brother 4 ] [http://s1.shard.jp/olharder/accessory-automotive.html pedagogia da autonomia ] microbiology research jobs in australia [http://s1.shard.jp/losaul/australian-landscape.html australian customs duty on cameras ] url antivirus stop sign [http://s1.shard.jp/frhorton/xntk9qgnd.html south africa health issues ] [http://s1.shard.jp/galeach/new119.html kaveh afrasiabi harvard ] [http://s1.shard.jp/galeach/new31.html a political map of south east asia ] [http://s1.shard.jp/losaul/exchange-rate-australian.html mothers day australia 2005 ] [http://s1.shard.jp/olharder/email-promotions.html autogas lpg conversion ] [http://s1.shard.jp/frhorton/8vpfwob3s.html somewhere in africa movie ] domain [http://s1.shard.jp/galeach/new164.html khasiat gamat ] map [http://s1.shard.jp/galeach/new14.html asian girl galleries ] [http://s1.shard.jp/losaul/south-african.html anglo australian observatory ] [http://s1.shard.jp/galeach/new81.html asiann ] [http://s1.shard.jp/galeach/new183.html anastasia anya journey ] domain [http://s1.shard.jp/olharder/automated-gasoline.html autobiographical essay example ] [http://s1.shard.jp/frhorton/9viywdetn.html african peoples education defense fund ] [http://s1.shard.jp/bireba/latest-antivirus.html virus y antivirus ] [http://s1.shard.jp/frhorton/9vces3l25.html african american trivia quiz ] [http://s1.shard.jp/frhorton/jaqhtnv6f.html estate duty south africa ] bosch oil painting african sea [http://s1.shard.jp/bireba/antivirus-check.html mcafee antivirus programs ] [http://s1.shard.jp/losaul/lawn-bowls-clubs.html cheap auto parts australia buy online ] [http://s1.shard.jp/galeach/new22.html nyc escorts asian ] [http://s1.shard.jp/frhorton/8qgvhwuw2.html african chimera violet ] australia uranium mining [http://s1.shard.jp/galeach/new111.html asian black hardcore ] [http://s1.shard.jp/galeach/new127.html asian wife pictures ] [http://s1.shard.jp/losaul/06-australia.html bunnings australia ] [http://s1.shard.jp/bireba/antivirus-comparison.html antivirus stop ] i bless the rains down in africa lyrics top [http://s1.shard.jp/losaul/job-agencies-sydney.html australian open tennis history ] [http://s1.shard.jp/olharder/autokillercom.html advanced auto care ] [http://s1.shard.jp/galeach/new135.html mr chew asia ] [http://s1.shard.jp/bireba/escan-antivirus.html kaspersky antivirus file server 5.0.40 key ] http [http://s1.shard.jp/losaul/auction-houses.html colourbond roofing australia ] [http://s1.shard.jp/bireba/cheap-norton-antivirus.html spy antivirus ] link [http://s1.shard.jp/frhorton/jp87fttqi.html african goose grey ] [http://s1.shard.jp/frhorton/lr43ii5kv.html african women seeking men ] [http://s1.shard.jp/galeach/new36.html asiatic carpets ] [http://s1.shard.jp/olharder/art-auto-ltd.html texas bill of sale automobile free ] [http://s1.shard.jp/olharder/teleflex-automotive.html japan auto exporters ] http map [http://s1.shard.jp/losaul/ice-tv-australia.html history of halloween in australia ] index norton antivirus 2005 keys [http://s1.shard.jp/olharder/discount-import.html autoplay menu builder v4.2 serial ] [http://s1.shard.jp/frhorton/h9wk8xs2j.html african warrior pictures ] desktop magazine australia http://www.textrotrsitde.com
If you use email, it's likely that you've recently been visited by a piece of spamÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂ¢ÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂan unsolicited, unwanted message, sent to you without your permission. If you manage an email system, it's almost certain that you've had to help your users avoid the deluge of unwanted email.
System administrators pay for spam with their time. The Internet's email system was designed to make it difficult to lose email messages: when a computer can't deliver a message to the intended recipient, it does its best to return that message to the sender. If it can't send the message to the sender, it sends it to the computer's postmasterÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂ¢ÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂbecause something must be seriously wrong if both the email addresses of the sender and the recipient of a message are invalid.
The well-meaning nature of Internet mail software becomes a positive liability when spammers come into the picture. In a typical bulk mailing, anywhere from a few hundred to tens of thousands of email addresses might be invalid. Under normal circumstances these email messages would bounce back to the sender. But the spammer doesn't want them! To avoid being overwhelmed, spammers often use invalid return addresses. The result: the email messages end up in the mailboxes of the Internet postmasters, who are usually living, breathing system administrators.
System administrators at large sites are now receiving hundreds to thousands of bounced spam messages each day. Unfortunately, each of these messages has to be carefully examined, because mixed in with these messages are the occasional bounced mail messages from misconfigured computers that actually should be fixed.
As the spam problem grows worse and worse, system administrators are increasingly taking themselves off their computers' "postmaster" mailing lists. The result is predictable: they're deluged with less email, but problems that they would normally discover by receiving postmaster email are being missed as well. The Internet as a whole suffers as a result.
Although there are many important ways to reduce spamÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂ¢ÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂincluding obscuring email addresses, complaining to spammers' service providers, and seeking legal and legislative reliefÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂ¢ÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂfew remedies are as immediately effective as filtering email messages on the basis of content and format, and few filtering systems are as widely used and well maintained as SpamAssassinÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂ¢ÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂ¢.
This book is for mail system administrators, network administrators, and Internet service providers who are concerned about the growing toll that spam is taking on their systems and their users and are looking for a way to regain some control or reduce the burden on their users.
Scope of This Book
This book is divided into nine chapters and one appendix. The first four chapters deal with core SpamAssassin concepts that are independent of the underlying mail system.
- Chapter 1
- Explains what SpamAssassin does, and provides a conceptual overview of its organization and features.
- Chapter 2
- Covers the installation, testing, and basic operation of SpamAssassin.
- Chapter 3
- Details the configuration of SpamAssassin, and focuses particularly on SpamAssassin's spam-detection rules. It explains how to increase or decrease the impact of rules, write new rules, and add addresses to blacklists and whitelists.
- Chapter 4
- Reviews the learning features of SpamAssassin: automatic whitelisting and Bayesian filtering. It provides the theory behind these features and discusses how to configure, train, and tune them.
The remaining five chapters detail the integration of SpamAssassin with several popular mail transport agents (MTAs) to provide sitewide spam-checking. They also explain how to set up a SpamAssassin gateway to check all incoming mail before delivery to an internal mail host.
- Chapter 5
- Explains how to integrate SpamAssassin with the sendmail MTA, using the milter interface. As an example of this approach, the installation and configuration of MIMEDefang is described.
- Chapter 6
- Explains how to integrate SpamAssassin with the Postfix MTA, using the content_filter interface. As an example of this approach, the installation and configuration of amavisd-new, a daemonized content filter, is described.
- Chapter 7
- Explains how to integrate SpamAssassin with the qmail MTA.
- Chapter 8
- Explains how to integrate SpamAssassin with the Exim MTA using several different popular approaches including custom transports, exiscan, and sa-exim.
- Chapter 9
- Explains how to set up a SpamAssassin POP mail proxy to support users who download their email with POP clients.
The Appendix lists useful resources for more information about SpamAssassin and other antispam approaches.
Versions Covered in This Book
At the time this book went to press, SpamAssassin 2.63 was the latest released version of SpamAssassin and was in wide use. The next-generation release of SpamAssassin, SpamAssassin 3.0, was available for beta-testing and is expected to be released at about the time this book appears in stores. SpamAssassin 3.0 introduces several important new features and changes parts of the Perl API.
Accordingly, this book covers both versions of SpamAssassin. When a topic or setting is specific to one version, I so note it.
Conventions Used in This Book
The following conventions are used in this book:
- Used for Unix file, directory, user, and group names and for Perl modules, objects, method names, and method options. It is also used for example URLs (uniform resource locators) and to emphasize new terms and concepts when they are introduced.
- Constant Width
- Used for Unix commands, code examples, and system output. It is also used for scripts, process names, and SpamAssassin directives.
- Constant Width Italic
- Used in examples for variable input (e.g., a filename you must provide).
- The Unix Bourne shell or Korn shell prompt.
- The Unix superuser prompt. I use this symbol for examples that should be executed by root.
This icon designates a note, which is an important aside to the nearby text.
This icon designates a warning related to the nearby text.
Using Code Examples
All the code in this book is available for download from http://www.oreilly.com/catalog/spamassassin. See the file readme.txt in the download for installation instructions.
This book is here to help you get your job done. In general, you may use the code in this book in your programs and documentation. You do not need to contact us for permission unless you're reproducing a significant portion of the code. For example, writing a program that uses several chunks of code from this book does not require permission. Selling or distributing a CD-ROM of examples from O'Reilly books does require permission. Answering a question by citing this book and quoting example code does not require permission. Incorporating a significant amount of example code from this book into your product's documentation does require permission.
We appreciate, but do not require, attribution. An attribution usually includes the title, author, and publisher; for example: "SpamAssassin, by Alan Schwartz (O'Reilly)."
If you feel your use of code examples falls outside fair use or the permission given previously, feel free to contact us at email@example.com.
Comments and Questions
We have tested and verified the information in this book to the best of our ability, but you may find that features have changed (or even that we have made mistakes!). Please let us know about any errors you find, as well as your suggestions for future editions, by writing to:
O'Reilly Media, Inc.
1005 Gravenstein Highway North
Sebastopol, CA 95472
(800) 998-9938 (U.S. and Canada)
(707) 827-7000 (international/local)
(707) 829-0104 (fax)
You can also contact O'Reilly by email. To be put on the mailing list or request a catalog, send a message to:
We have a web page for this book, which lists errata, examples, and additional information. You can access this page at:
To comment or ask technical questions about this book, send email to:
For more information about O'Reilly books, conferences, Resource Centers, and the O'Reilly Network, see the O'Reilly web site at:
Bob Amen, Justin Mason, and Matt Riffle served as technical reviewers for this book. Any remaining errors, of course, are mine.
I have once again had the pleasure of collaborating with an excellent O'Reilly editor, Jonathan Gennick. The O'Reilly production crew for this book included Darren Kelly, Ellie Volckhausen, and Nancy Crumpton.
This book is dedicated to the developers and user community of SpamAssassin, for their fine work in helping to stem the flood of unwanted email.
Never-ending thanks to M.G. and Ari, who make it all worthwhile.
- ↑ Spam is also a registered trademark of Hormel Foods, which uses the word to describe a canned luncheon meat. In this book, the word "spam" is used exclusively to refer to Internet spam and not the meat.