RE: email address "spoofed"

From: Aditya, ALD [Aditya Lalit Deshmukh] (aditya.deshmukh_at_online.gateway.technolabs.net)
Date: 03/13/04

  • Next message: chumma chumma: "Which one have more vulnerability history, SSH or OpenSSH ?" 
    To: <gillettdavid@fhda.edu>, <ald2003@users.sourceforge.net>, <hometeam@goeaston.net>, "'security-basics'" <security-basics@securityfocus.com>
Date: Sat, 13 Mar 2004 10:25:19 +0530

    >
    > A great many ISPs who hand out addresses via DHCP maintain a
    > set of generic reverse-DNS entries for their scopes. On the one
    > hand, this greatly diminishes the value of this lookup as an
    > anti-spam measure; on the other hand, it avoids the particular
    > problem you describe.

    the problem is that my address when forward resolved is different from reverse resolution.

    > A more effective measure employed by several ISPs is to block
    > outbound SMTP at their borders, except for their own officially
    > sanctioned email server(s). This cuts the propagation of viruses
    > with their own SMTP engine, and use of spam-sending packages with
    > their own, to virtually nil, and if they don't turn on the reverse
    > check, they can probably (*safely*) avoid setting up reverse
    > records for their DHCP scopes.

    this would work only if the isp allowed any and every email from any domain to pass through, that is why i run myy own mail server with the A and MX recored pointing to my smtp server address

    > If your ISP allows arbitrary port 25 traffic to the world, but
    > won't set up reverse ranges on its DNS servers, maybe you should
    > evaluate some of their competitors....
    >

    ther competitors are worse, atleast this one has a very responcive help desk and good people at the phone and not some script monkeys, one call is what it takes to resolve any complicated matter.

    -aditya

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  • Next message: chumma chumma: "Which one have more vulnerability history, SSH or OpenSSH ?"

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