I have a public mail server (Linux + postfix) and some clients using it. The server is properly configured, included DKIM and SPF validation. But emails from only a few of my clients are being marked as SPAM, because the client-ip doesn't match with allowed senders' IPs and the SPF validation fails:
Received-SPF: fail (google.com: domain of xxxxx@xxxxxx.com does not designate 217.125.48.20 as permitted sender) client-ip=217.125.48.20;
Of course, 217.125.48.20 is not the IP of my server.
I don't know the reason, because they are sending mails from properly (AFAIK) configured Outlooks. Even though, the DKIM validation pass, so, the email pass through my server before is sent.
Has anybody experienced similar issues and could tell me any possible reasons for that mismatch?
Here are the headers (mailboxes have been replaced by xxxxx):
Delivered-To: xxxxxxx@gmail.com
Received: by 10.194.70.103 with SMTP id l7csp1376984wju;
Fri, 2 Sep 2016 04:49:17 -0700 (PDT)
X-Received: by 10.28.154.208 with SMTP id c199mr2895670wme.102.1472816956397;
Fri, 02 Sep 2016 04:49:16 -0700 (PDT)
Authentication-Results: mx.google.com;
spf=fail (google.com: domain of xxxxxxx@afanascadiz.com does not designate 217.125.48.20 as permitted sender) smtp.mailfrom=xxxxxxx@afanascadiz.com;
dkim=pass header.i=@cydsur.com
Received-SPF: fail (google.com: domain of xxxxxx@afanascadiz.com does not designate 217.125.48.20 as permitted sender) client-ip=217.125.48.20;
Received: by 10.28.127.2 with POP3 id a2mf7718962wmd.1;
Fri, 02 Sep 2016 04:49:16 -0700 (PDT)
X-Gmail-Fetch-Info: xxxxxxx@staffgrupom.es 1 ns.cydsur.com 995 xxxxxxxx@staffgrupom.es
Return-Path: <xxxxxxx@afanascadiz.com>
Delivered-To: xxxxxxxx@staffgrupom.es
Received: from DANIEL (20.red-217-125-48.staticip.rima-tde.net [217.125.48.20])
(Authenticated sender: xxxxxxxx@afanascadiz.com)
by ns.cydsur.com (Postfix) with ESMTPSA id 1D985330D3F1;
Fri, 2 Sep 2016 13:45:14 +0200 (CEST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cydsur.com; s=mail;
t=1472816717; bh=8OGFi38ZIKFm+jXd0aJbg6pZnAOtjZMC4U8yHU+Tpm4=;
h=From:To:Cc:Subject:Date:From;
b=OaGmCrOIBLREC3z5kJt4Z91CTK7caJY0FQvYtTQBiJjrAiK4HQw1/LotUW9g7DuZQ
SOchVeXw7Filp0smGGOdVnJWrSdHEWT74SwqWTULmpYxIHOds68HOIWwJJKR8rxLOe
a+TidmwP93Zua4ETN51zqU/QVtB9I1oefxd0W0B0=
From: =?iso-8859-1?Q?XXXXXXXXXXXXXX?= <xxxxxxx@afanascadiz.com>
To: <xxxxxx@cydsur.com>,
<xxxxxxx@staffgrupom.es>
Cc: "'XXXXXXX'" <xxxxxxxr@afanascadiz.com>
Subject: RV: ctas de usuarios.
Date: Fri, 2 Sep 2016 13:45:16 +0200
Message-ID: <000301d2050f$7a7d3540$6f779fc0$@com>
MIME-Version: 1.0
Content-Type: multipart/related;
boundary="----=_NextPart_000_0004_01D20520.3E060540"
X-Mailer: Microsoft Office Outlook 12.0
Thread-Index: AdHjLl7+vxyBNVQdQIWvJApRimDm9gh3o/5Q
Content-Language: es
X-Spam-Status: No, score=-0.7 required=5.0 tests=ALL_TRUSTED,BAYES_00,
HTML_MESSAGE,TVD_RCVD_SINGLE,T_KAM_HTML_FONT_INVALID,URIBL_BLOCKED
autolearn=no autolearn_force=no version=3.4.0
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on ns.cydsur.com
X-Virus-Scanned: clamav-milter 0.98.7 at ns.cydsur.com
X-Virus-Status: Clean