Op 22-10-16 om 04:32 schreef Bill Cole: > On 21 Oct 2016, at 16:15, Paul van der Vlis wrote:
>> ---- >> Received: from [127.0.0.1] (87-92-55-206.bb.dnainternet.fi >> [87.92.55.206]) >> (Authenticated sender: p...@puk.nl) >> by mail.vandervlis.nl (Postfix) with ESMTPSA id 774B23E0285; >> Fri, 21 Oct 2016 18:57:14 +0200 (CEST) >> ---- >> As would my server sent it to my server... > > Not exactly. That Received header indicates that the machine at > 87.92.55.206 which is actually named 87-92-55-206.bb.dnainternet.fi > introduced itself with "EHLO [127.0.0.1]" on an encrypted session and > proceeded to authenticate as the user whose name you've replaced with > p...@puk.nl. > > As a stopgap, you could add a directive like this to > smtpd_helo_restrictions: > > check_helo_access pcre:/etc/postfix/helo_checks > > And in that helo_checks file; > > /127\.0\.0\.1/ REJECT you are not me Thanks, a great idea to have standard in most cases. > This will catch and reject formally correct IP literals as in this case > and the more common bare IP form of claiming to be localhost. There's no > reason for any mail client ever to say "EHLO [127.0.0.1]" except to > cause a MTA to generate a confusing Received header. Right. With regards, Paul van der Vlis. -- Paul van der Vlis Linux systeembeheer Groningen https://www.vandervlis.nl/
