* Ricardo Fitzgerald (axis@movinet.com.uy) [020926 09:56]: > Hi to all, > > Recently I had a very bad news one of my clients mail server was blocked due > to spamming !!! Well, the thing is they are not spamming at all, but their > ip was used by some unscrupulous spammer, now I have the task to write some > security to prevent that but I don't know much about the subject, where can > I find some info to develop a good firewall or sendmail rules to prevent > that from happen again ? I've recently started to use sendmail and it's > somewhat obscure, due to my personal situation I can't even afford to buy a > book on sendmail so I need free sources. > Any suggestions from experienced users are welcomed, now I have sendmail, > and fetchmail, procmail and squid as proxy to serve the internal lan of 5 > windows computers. Start here: http://www.google.com/search?q=sendmail+open+relay and read read read read read. I don't speak sendmail fluently, but it should be an easy task to close an open relay. If you can't do it easily with sendmail, and you're not rather too attached to sendmail (sounds like you don't understand it anyway (but don't take that comment the wrong way)) install exim instead, and be merry. It's easy to set up and easy to configure, and the default install is not an open relay. (I don't mean to imply that sendmail's default install is; in fact I doubt that that is the case. But $OP's current sendmail setup is configured as such, and a new default exim's configuration would be at least one notch better in that regard.) good times, Vineet -- http://www.doorstop.net/ -- "Extremism in the defense of liberty is no vice. Moderation in the pursuit of justice is no virtue." -- Barry Goldwater
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