Well, at the high end of the spam game they do tests to see if an address is valid or not.. such things as image links in email that are actually links to a server side script at their end that is passed an id matching the email address that that particular message was addressed to.
Also some record if the message was bounced or not, and this is where bouncing the spam back can be handy.. because the email address will not be validated as accepted and therefore it might be removed from the spammers Database. Since many spammers use fake yahoo address's to send a ton of mail out in a short time, overloadign their accounts with bounced messages is a good thing too. It will have a likewise beneficial effect on ISP's like the russian spam servers, whereby a huge stream of bounce messages uses up some of the servers bandwidth, and costs them money.. so they would be more inclined to do something about it. A last benefit is the ego... its great to feel that you are being active rather then reactive with regards to spam.. filtering just doesnt' feel as good as rejecting spam... :-) Right now this sort of thing is the best method we have for reducing spam that is unintrusive (unlike challenge response methods). They guys that come up with stuff like postfix proxy are legends (and WV, the creator and maintainer of postfix (and tcp wrappers) is a surprisingly nice guy, (unlike D Beirnstein (qmail), who is an egocentrical ellitist)) both are undoubtably brilliant though. regards Franki -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Martin Fahrendorf Sent: Wednesday, 23 July 2003 5:55 PM To: [EMAIL PROTECTED] Subject: Re: [expert] Using Postfix to send mail. Am Mittwoch, 23. Juli 2003 10:49 schrieb Joerg Mertin: > Hi Martin, > > thx for the hint. I might give it a try. > However - what buzzes me here is that if you use the proxy method to > identify spam - you have to get the spam anyway through it - don't you ? So > - the spam will use your bandwidth to get analyzed by the "proxy" > application - and the proxy application then returns a Spam-Detected > message which will be interpreted by the postfix process and which will > make that one reject the message definitly. > > IMHO - the only difference is that the remote side will get a reject > message if I understood correctly the process. Please correct me if I'm > wrong. Jepp, that's right. > > Do you think this reject message will inhibit spammers to send you more > mail ? Hm, that is wild guessing. I think spamers dont want to waste bandwith, they want to get their mails read. If you silently delete the spam the spamer don't know if their mails get read or not. So they assume thei can send their mails again. If the spam get rejected they know that you don't accept the mail. It is up to the sending server to handle the rejection. Do they send spam again? Yes, I fear they see it as a kind of sport to get their spam trough. But doing nothing is no sollution. > > NOTE - the actual spamassassin/postfix/anomy method enables you to actually > get the Mail in, spamassassin checks it through spamc/spamd - and if it's > beeing detected a SPAM - you can tell the delivery script to delete it or > move it to a local-file for laer analysis ... > > Cheers > > Joerg > Martin -- ------------------------------------------------------------ H E L I X Gesellschaft f�r Software & Engineering mbH ------------------------------------------------------------ Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 ------------------------------------------------------------ http://www.helix-gmbh.net [EMAIL PROTECTED] ------------------------------------------------------------
Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
