Len, Was wondering if you had taken a look at something called SpamCannibal at http://www.spamcannibal.org . It is something akin to the Anvil feature you describe, but with a twist. The stated aim of the daemon on its website is, "SpamCannibal's TCP/IP tarpit stops spam by telling the spam server to send very small packets. SpamCannibal then causes the spam server to retry sending over and over - ideally bringing the spam server to a virtual halt for a long time or perhaps indefinitely."
I haven't tried setting up a Postfix box for this yet, but it sounds like fun. :-) William Van Hefner Network Administrator Vantek Communications, Inc. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Len Conrad > Sent: Wednesday, January 26, 2005 7:22 AM > To: IMail_Forum@list.ipswitch.com > Subject: Re: [IMail Forum] Filanet InterJak 200 > > > > >If you're willing to get your hands dirty and learn a bit of *nix I > >recommend pf on OpenBSD which is _very_ flexible and will let you > >'tarpit' spammers (with spamd) if you wish. It's free and it'll run > >very well on a pII 350mhz with 128m of RAM. It is a bit of > a learning > >curve if you're a Windows only guy but well worth it IMHO. > > Even easier is IMGate/postfix's "anvil" feature which will > dynamically > smtp-blocks/rate-limits any IP that connects to postfix more > than x times > in y minutes. > > anvilled IPs connect to port 25, postfix sends an immediate > SMTP 421 code, > and hangs up. postfix can probably do that 200 times/second without > impacting legit operation. > > I would say the majority of msgs to unknown users come from > subscriber > access networks of millions infected PCs, each of which > doesn't attack any > one MX at a high rate of attempts, so rate limiting is not helpful. > > Len > > > > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > List Archive: > http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
