This post originated from an RSS feed registered with Java Buzz
by Marc Logemann.
Original Post: increased the bar for spammers
Feed Title: Logemann Blog
Feed URL: http://feeds.feedburner.com/LogemannBlog
Feed Description: Marc Logemann's thoughts on java and other stuff
Unfortunately in a small company like mine, you have to do all sorts of things which are not in your prime focus. Maintaining a public postfix mailserver is one of these things. Since a few weeks i am frustrated about the spam percentage i am getting and all the false positives my client scanner is detecting.
It was time to dig deepter into postfix and thanks to google and the very helpful german maillist "postfixbuch-users". I think i ve managed to really get to a new level. Of course things need to be validated again in a few days but thats what i have done:
1) used policyd-weight to kill all the seperate DNSBL entries in postfix and use a software that uses all the importants blacklists, together with a useful weighing system.
2) use greylisting with "postgrey"
3) used some postfix internal checks that were suggested on the mentioned list
Of course, before my refactoring was done, i also had some DNSBL and some other restrictions in postfix but it seems a bit weird all in all and not organized very well. Another interessting thing is, when you follow mail.log carefully for some hours, you really get scared how much bullshit a SMTP Server has to handle. Of course everyone knows from the press that the spam percentage is that high compared to ham, but when you see it live, its even more scary.... Alone the fact that one needs to buy some amount of hardware to handle all that spam is making me angry.
Previous Topic
