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Re: Discovering users by RCPT TO

Subject: Re: Discovering users by RCPT TO
Date: Sat, 15 Jan 2005 10:35:19 +0200
dmz wrote:
I see spammers hitting my MTA daily with dictionary RCTP TO queries
and there isn't much you can really do against it; however I have been
thinking about a solution using real time blockers.

The idea is to monitor the logfile of the MTA, looking for a host
getting more than "X" failed destination addresses (I think 2 or 3 is
a nice entry threshold). Then when they reach the threshold their IP
gets put into a local DNS server that is used by the MTA to as a real
time blocker.

This wouldn't' require more than another RBL addition to the MTA and
then an external script tied to either bind or djbdns.

thoughts?
dmz

But wouldn't that be vulnerable to a DoS attack, IE spoofing the IP and denying service to legitimate clients?


--
[Name      ]   ::  [Matan I. Peled    ]
[Location  ]   ::  [Israel            ]
[Public Key]   ::  [0xD6F42CA5        ]
[Keyserver ]   ::  [keyserver.kjsl.com]
encrypted/signed  plain text  preferred

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