[Mimedefang] Requiring FQDN in HELO

Rob MacGregor rob.macgregor at gmail.com
Wed Dec 28 13:45:25 EST 2005


On 28/12/05, Dirk the Daring <dirk at psicorps.org> wrote:
>    I've noticed a lot of SPAM does not have an FQDN in the HELO. It'll
> have just "localhost" or even omit a hostname entirely. Obviously, if
> the HELO is an IP address in square brackets, that's fine.
>
>    Is there any danger of rejecting "legitimate" E-Mail if I write my
> mimedefang-filter to:
>
>         1) Absent an IP address in square brackets, require a
>                 an alphanumeric string in the HELO
>
>         2) Reject a HELO where the alphanumeric string is not
>                 a FQDN (using a regex looking for at least
>                 one "." in the HELO string)

A number of MUAs, including Outlook, will AFAIK fall foul of that requirement.

--
                 Please keep list traffic on the list.
Rob MacGregor
      Whoever fights monsters should see to it that in the process he
        doesn't become a monster.                  Friedrich Nietzsche



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