Re: Best method to handle invalid HELO hostnames?

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Best method to handle invalid HELO hostnames?
\ Justin Piszcz (16 Mar 2008)
. \ mouss (16 Mar 2008)
. . \ Justin Piszcz (16 Mar 2008)

3 msg	How to block certain tld's

Subject:	Re: Best method to handle invalid HELO hostnames?
Group:	Postfix-users
From:	Justin Piszcz
Date:	16 Mar 2008

On Sun, 16 Mar 2008, mouss wrote:

> smtpd_restrictions_classes =
> ...
> reject_unauth_destination
> ...
> check_helo_access pcre:/etc/postfix/maps/pcre/helo_acl
> ...
>
>
> # literal IP
> /^[/ reject_unknown_client, greylist
>
> # bogus TLDs
> /\.(arpa|invalid|example|localhost|test|localdomain)$/ REJECT ...
>
> # probably misconfigured.
> /^localhost\./ reject_unknown_helo_hostname, reject_unknown_client
>
> # Two label helo should resolve
> /^[^\.]*\.[^\.]+$/ reject_unknown_helo_hostname
>
> # skip common gTLDs
> /\.(com|org|net|info|edu|gov|mil)$/ DUNNO
>
> # skip cc TLDs
> /\.[a-z]{2}$/ DUNNO
>
> # the rest must resolve
> /./ reject_unknown_helo_hostname
>
>

Extremely useful, thank you.

Justin.