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- Maybe in reply to: David Landgren: "Re: Rejecting naked_ip_address"
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From: David Landgren (no email)
Date: Wed Feb 02 2005 - 10:05:40 EST
Pollywog wrote:
[...]
> Well, this is what I have done in the past about those, which are almost
> always spam.
>
> /[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/ REJECT
>
> See smtpd_helo_restrictions in the documentation.
>
> I believe I stopped using it because every once in a while, it would catch
> legitimate mail coming from a misconfigured host. I sense a ripple in the
> continuum, that someone is going to tell me that a numeric HELO is not
> necessarily a misconfiguration.
No it's not, as long as it is an address literal, (i.e., in brackets).
My message will appear to come from a host with an IP address of
81.80.147.197. I would be annoyed the message was rejected because my
server announced itself with
HELO [81.80.147.197]
I would not be surprised if it was rejected because I announced myself as
HELO 81.80.147.197
..because so many spam engines do this, and it does not conform tot he
recommendations laid down in RFC 2821 section 4.1.3.
Of course, if you are rejecting legitimate mail once in a while you
can't perform such a check. I look at it as a cost/benefit analysis. The
check doesn't cost much, and it traps a lot. YMMV
David
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