[Mimedefang] filter-relay, rejection on bogus helo

Paul Heinlein heinlein at madboa.com
Wed Jan 7 12:35:31 EST 2004


On Wed, 7 Jan 2004, Bryan Stansell wrote:

> if you really want things that don't have a '.', i'd use
>
> if ($helo !~ /\./) {}
>
> if someone used 'HELO me!', your check wouldn't match...any
> non-alphanumeric characters (besides '_') look the same to your
> regex, so there are many non-'.' characters you could use to bypass
> the check.

FYI: Windows clients will sometimes (often? always?) use an
unqualified NETBIOS name in SMTP handshaking.

-- Paul Heinlein <heinlein at madboa.com>



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