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reject_unknown_helo_hostname and an address literal

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  • Nikolas Kallis
    Hello, If I use the smtpd_helo_restrictions option parameter reject_unknown_helo_hostname , will a hostname that is an address literal be rejected? Regards,
    Message 1 of 2 , May 12, 2013
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      Hello,



      If I use the 'smtpd_helo_restrictions' option parameter
      'reject_unknown_helo_hostname', will a hostname that is an address
      literal be rejected?



      Regards,

      Nikolas Kallis
    • /dev/rob0
      ... FWIW, you don t have to use it in smtpd_helo_restrictions; other restriction stages can have HELO-based restrictions also. See SMTPD_ACCESS_README.html for
      Message 2 of 2 , May 13, 2013
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        On Mon, May 13, 2013 at 04:30:51PM +1000, Nikolas Kallis wrote:
        > If I use the 'smtpd_helo_restrictions' option parameter
        > 'reject_unknown_helo_hostname',

        FWIW, you don't have to use it in smtpd_helo_restrictions; other
        restriction stages can have HELO-based restrictions also. See
        SMTPD_ACCESS_README.html for the overview.

        > will a hostname that is an address literal be rejected?

        No. (I think per RFC 5321, an address literal is not the same as a
        hostname, by way of explanation. *_hostname restrictions are only
        applied to hostnames.)

        But I willfully reject address literal HELOs on port 25. A mail-
        exchanging host should have a real hostname. By local policy
        decision, I only consider an address literal HELO as valid if given
        by a user's MUA on submission. I've never known of a loss of real
        mail as a result of this policy.

        Perhaps what you really need is to separate your submission stream
        from your MX inbound stream. If you can't/won't force users off of
        port 25, you could use a different IP.add.re.ss:25 as your MX, and
        leave the old one to your users.
        --
        http://rob0.nodns4.us/ -- system administration and consulting
        Offlist GMX mail is seen only if "/dev/rob0" is in the Subject:
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