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Hello,
The title says pretty much everything I am currently facing with right now. To be more precise:
I run my own mail server and have successfully configured DKIM. There are bunch of websites out there to validate the correctness of the configuration. One of them is http://dkimvalidator.com which I am using for my tests.
Now the issue is when sending a HTML email using App Suite within a browser the email is somehow modified in a way that the DKIM signature seems to be invalid. Sending a HTML email using iOS (connected via ActiveSync to App Suite) does not show this behaviour. Also sending a plain text email using the browser passes the DKIM signature validation.
So the question is: what is App Suite modifying (I assume the bold text below) and why?
Below the output of dkimvalidator.com
Thank you in advance.
The title says pretty much everything I am currently facing with right now. To be more precise:
I run my own mail server and have successfully configured DKIM. There are bunch of websites out there to validate the correctness of the configuration. One of them is http://dkimvalidator.com which I am using for my tests.
Now the issue is when sending a HTML email using App Suite within a browser the email is somehow modified in a way that the DKIM signature seems to be invalid. Sending a HTML email using iOS (connected via ActiveSync to App Suite) does not show this behaviour. Also sending a plain text email using the browser passes the DKIM signature validation.
So the question is: what is App Suite modifying (I assume the bold text below) and why?
Below the output of dkimvalidator.com
Code:
Received: from (xx.xx.xx [xx.xx.xx.xx])
by relay-6.us-west-2.relay-prod (Postfix) with ESMTPS id 72A1C4602D3
for <SOd3Q73lgQ68MG@dkimvalidator.com>; Wed, 4 Apr 2018 13:21:58 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xx.xx; s=x;
h=Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Message-ID:To:From:Date; bh=BlRU/qV0gCahvmOMcaCPoX/COkmMOSka4cLG/PQ+zjM=;
b=HSLWZDQj7mz6vZNblRig0j/EcU1JFrkuVQNZUFLa1gztOL6XxRU69qhGmooMcbCH1aBp6g4VBp1JUhpwIrgOn2vjCDBBYtbDL3kgt4EIZqKD2jfOLQLcXw823i6tjVKIYldD4cr8FLkoefdqrvK41NQU4sRschBO53dz8Gjn4d9Q3OLSQiFwwxSQT0R3fKA5dPz08nNtoXh0Vg4qRTRMaa7X7h42Kb+pLC7sbK8obMDOp2P5SxSjFa/TlRTfUxsi1k5OX4vRJWWZnJcmgreKgJ2xg+M4P5dxJFtatz3/IfCtDHXdlkXLB2AlyvDI41gNE+XTM1wRLKkTsoIPx/FYrA==;
Received: from localhost ([127.0.0.1] helo=null)
by xx.xx.xx with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256)
(Exim 4.84_2)
(envelope-from <xx@xx.xx>)
id 1f3iMM-000Etp-MG
for SOd3Q73lgQ68MG@dkimvalidator.com; Wed, 04 Apr 2018 15:21:56 +0200
Date: Wed, 4 Apr 2018 15:21:54 +0200 (CEST)
From: xx xx <xx@xx.xx>
To: SOd3Q73lgQ68MG@dkimvalidator.com
Message-ID: <1037496807.51.1522848114492@xx.xx>
Subject: [No Subject]
MIME-Version: 1.0
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 7bit
X-Priority: 3
Importance: Medium
X-Mailer: Open-Xchange Mailer v7.8.4-Rev25
X-Originating-Client: open-xchange-appsuite
X-Spam_score: 0.1
X-Spam_score_int: 1
X-Spam_bar: /
X-Spam_report: Spam detection software, running on the system "xx.xx.xx",
has NOT identified this incoming email as spam. The original
message has been attached to this so you can view it or label
similar future email. If you have any questions, see
the administrator of that system for details.
Content preview: [...]
Content analysis details: (0.1 points, 5.0 required)
pts rule name description
---- ---------------------- --------------------------------------------------
-1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP
1.1 MIME_HTML_ONLY BODY: Message only has text/html MIME parts
0.0 HTML_MESSAGE BODY: HTML included in message
0.0 TVD_SPACE_RATIO No description available.
[B]<!DOCTYPE html>
<html><head>
<meta charset="UTF-8">
</head><body></body></html>[/B]
Message contains this DKIM Signature:
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xx.xx; s=x;
h=Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Message-ID:To:From:Date; bh=BlRU/qV0gCahvmOMcaCPoX/COkmMOSka4cLG/PQ+zjM=;
b=HSLWZDQj7mz6vZNblRig0j/EcU1JFrkuVQNZUFLa1gztOL6XxRU69qhGmooMcbCH1aBp6g4VBp1JUhpwIrgOn2vjCDBBYtbDL3kgt4EIZqKD2jfOLQLcXw823i6tjVKIYldD4cr8FLkoefdqrvK41NQU4sRschBO53dz8Gjn4d9Q3OLSQiFwwxSQT0R3fKA5dPz08nNtoXh0Vg4qRTRMaa7X7h42Kb+pLC7sbK8obMDOp2P5SxSjFa/TlRTfUxsi1k5OX4vRJWWZnJcmgreKgJ2xg+M4P5dxJFtatz3/IfCtDHXdlkXLB2AlyvDI41gNE+XTM1wRLKkTsoIPx/FYrA==;
Signature Information:
v= Version: 1
a= Algorithm: rsa-sha256
c= Method: relaxed/relaxed
d= Domain: xx
s= Selector: x
q= Protocol: dns/txt
bh= BlRU/qV0gCahvmOMcaCPoX/COkmMOSka4cLG/PQ+zjM=
h= Signed Headers: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Message-ID:To:From:Date
b= Data: HSLWZDQj7mz6vZNblRig0j/EcU1JFrkuVQNZUFLa1gztOL6XxRU69qhGmooMcbCH1aBp6g4VBp1JUhpwIrgOn2vjCDBBYtbDL3kgt4EIZqKD2jfOLQLcXw823i6tjVKIYldD4cr8FLkoefdqrvK41NQU4sRschBO53dz8Gjn4d9Q3OLSQiFwwxSQT0R3fKA5dPz08nNtoXh0Vg4qRTRMaa7X7h42Kb+pLC7sbK8obMDOp2P5SxSjFa/TlRTfUxsi1k5OX4vRJWWZnJcmgreKgJ2xg+M4P5dxJFtatz3/IfCtDHXdlkXLB2AlyvDI41gNE+XTM1wRLKkTsoIPx/FYrA==
Public Key DNS Lookup
Building DNS Query for x._domainkey.xx.xx
Retrieved this publickey from DNS: v=DKIM1; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuqWwWj0icI3OYy8xuFlSrAWR/nexz2xHDUmdUaJYOBjMyNs3lblzYXNCOpmCuROZL7QstAvZSF0MBS5rxYZasdFHhT1Bc4g4OVaNtVZI/I8wYcp0D6eGoGSX5qOXQc7ruvTiqed9jnG3X3rS0hdcF8PLVb1WSi00W+mqzvSzMSVXuE9jd1Fqk5L+/0RIZfmuDD+yNf4Z3TZ3j/soKN4fbt5QiVYWYozumv4g7Sk0wbPB1ekUSwIc3DbjbI7lAqMVqbKyImeNyRxt78B3g4d4LRMDL03Ug7PM3OFgP4m+kDiOiRTw5wJKhEzLjPv6IR0RXZKTtr/cM7J7CNrLZxCI5wIDAQAB
Validating Signature
result = fail
Details: body has been altered
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