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Re: how to identify smtp servers for a domain?

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  • Arturo 'Buanzo' Busleiman
    ... Hash: SHA512 ... They might be listed in the TXT record, inside SPF: host -t txt somedomain.com But you should use SPF, then... - -- Arturo Buanzo
    Message 1 of 4 , Apr 30, 2008
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      Juan Miscaro wrote:
      | I'm trying to whitelist servers for a domain. I know how to find MX
      | servers (what server to send mail to for that domain) but many
      | organizations use separate servers to send their mail. How do I find
      | those sending (SMTP) servers so I can whitelist them?

      They might be listed in the TXT record, inside SPF:

      host -t txt somedomain.com

      But you should use SPF, then...

      - --
      Arturo "Buanzo" Busleiman
      Reliable inter-continental Mail Relay Service - Ask me!
      Independent Security Consultant - SANS - OISSG
      http://www.buanzo.com.ar/pro/
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    • Wietse Venema
      ... MX servers RECEIVE mail for domains. They don t have to be the same as the machines that SEND mail for a domain. There is a protocol called SPF that
      Message 2 of 4 , Apr 30, 2008
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        Juan Miscaro:
        > Hi,
        >
        > I'm trying to whitelist servers for a domain. I know how to find MX
        > servers (what server to send mail to for that domain) but many

        MX servers RECEIVE mail for domains. They don't have to be the
        same as the machines that SEND mail for a domain.

        There is a protocol called SPF that identifies sending machines,
        but only a minority of sites announces SPF records.

        Wietse

        > organizations use separate servers to send their mail. How do I find
        > those sending (SMTP) servers so I can whitelist them?
        >
        > /juan
        >
        >
      • Terry Carmen
        ... The only reliable way I m aware of is to ask the admin for the domain. This generally works well for smaller companies, but seems to be useless for big
        Message 3 of 4 , Apr 30, 2008
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          Juan Miscaro wrote:
          > Hi,
          >
          > I'm trying to whitelist servers for a domain. I know how to find MX
          > servers (what server to send mail to for that domain) but many
          > organizations use separate servers to send their mail. How do I find
          > those sending (SMTP) servers so I can whitelist them?
          >
          The only reliable way I'm aware of is to ask the admin for the domain.

          This generally works well for smaller companies, but seems to be useless
          for big operations like Yahoo, Microsoft, etc.

          Terry


          Terry
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