T
TDe7
Guest
Hello,
I've been troubleshooting email delivery and have it narrowed down to Outlook. We implement SPF and DKIM, with the goal of achieving full alignment. Our domain email sent through other apps, such as Postbox, deliver without issue and are fully aligned. The same domain email setup identically in Outlook will break DKIM alignment, saying the signature did not verify, wrong body hash. As a result, a lot of our domain email bounces back undeliverable or winds up in recipient's SPAM folders.
Looking at the email headers for various emails, I can see why. Looking below, and there are changes to the Content-Type and looks like Outlooks adds to the email in transit.
I've changed the encoding within Outlook from the default settings to UTF-8, but it didn't change anything, instead Outlook proceeded to encode the email however it saw fit.
Using Postbox and sending an identical email from same sender to same recipient yielded full alignment with encoding passing as UTF-8 and no extra 'NextPart' added.
Sample of email sent from Outlook:
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1572285895; s=zoho; d=email.com; i=*** Email address is removed for privacy ***; h=From:To:References:In-Reply-To:Subject
ate:Message-ID:MIME-Version:Content-Type; l=2911; bh=55oF4546764h4g4676t57574+Vtr7xAyCI+9fEOOLbGjyfa0E52iy36tJ5PPlFg=; b=Wdn3LaXGjO+zhoTfy6i7kmyhgfcR2EGR6DTJX+LVldSDEmWTdTm4gIQH3tLIzyTVwLe89UfbnfHF c5FFA6RUBPi+kxJd5qWA/Ek51MBizguuIO1rxckZfNT31UDp0tipm1LZj32J5MEvUpV i2YndTwcRMGokvyfNckz/J0WNBxXyjyj6trhjyhnben0nDbV2W/X4=
Received: from PC (12.345.67.89 [12.345.67.89]) by mx.zohomail.com with SMTPS id 1572285893097569.92580635065016; Mon, 28 Oct 2019 11:04:53 -0700
From: *** Email address is removed for privacy ***
To: <*** Email address is removed for privacy ***>
Subject: Outlook to Gmail
Date: Mon, 28 Oct 2019 14:04:51 -0400
Message-ID: <*** Email address is removed for privacy ***>
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="----=_NextPart_000_0091_01D58D98.AB7F9BF0"
X-Mailer: Microsoft Outlook 16.0
Thread-Index: AQMrjcYI76YKJTL13jlnlC+Yh/R+xaTEWLRw
Content-Language: en-us
X-ZohoMailClient: External
------=_NextPart_000_0091_01D58D98.AB7F9BF0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
From: *** Email address is removed for privacy *** <*** Email address is removed for privacy ***>
Sent: Monday, October 28, 2019 2:01 PM
To: *** Email address is removed for privacy *** <*** Email address is removed for privacy ***>
Subject: Outlook to Gmail
Testing testing testing
------=_NextPart_000_0091_01D58D98.AB7F9BF0
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
<html xmlns:v=3D"urn:schemas-microsoft-com:vml" xmlns
=3D"urn:schemas-micr=
osoft-comfficeffice" xmlns:w=3D"urn:schemas-microsoft-comffice:word" =
xmlns:m=3D xmlns=3D"http:=
//www.w3.org/TR/REC-html40"><head><meta http-equiv=3DContent-Type content=
=3D"text/html; charset=3Dutf-8"><meta name=3DGenerator content=3D"Microsoft=
Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
=09{font-family:"Cambria Math";
=09panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
=09{font-family:Calibri;
=09panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
=09{margin:0in;
=09margin-bottom:.0001pt;
=09font-size:11.0pt;
=09font-family:"Calibri",sans-serif;}
................................................ *** Email address is removed for privacy ***' =
<*** Email address is removed for privacy ***><br><b>Subject:</b>Outlook to Gmail<o
></o=
></p><p class=3DMsoNormal><o> </o></p><p class=3DMsoNormal>Testi=
ng testing testing<o></o></p></div></body></html>
------=_NextPart_000_0091_01D58D98.AB7F9BF0--
This is happening across multiple Windows 10 systems running different versions of Outlook, and possibly Outlook on mobile (I have not yet investigated if this is indeed the cause for the failures on mobile) and Outlook.com. Outlook is the common link across all failures.
Is there a setting I need to add or change somewhere in the settings to stop Outlook from doing this? If not, what is the workaround here to use Outlook but still pass fully aligned email?
Please let me know, thanks.
Continue reading...
I've been troubleshooting email delivery and have it narrowed down to Outlook. We implement SPF and DKIM, with the goal of achieving full alignment. Our domain email sent through other apps, such as Postbox, deliver without issue and are fully aligned. The same domain email setup identically in Outlook will break DKIM alignment, saying the signature did not verify, wrong body hash. As a result, a lot of our domain email bounces back undeliverable or winds up in recipient's SPAM folders.
Looking at the email headers for various emails, I can see why. Looking below, and there are changes to the Content-Type and looks like Outlooks adds to the email in transit.
I've changed the encoding within Outlook from the default settings to UTF-8, but it didn't change anything, instead Outlook proceeded to encode the email however it saw fit.
Using Postbox and sending an identical email from same sender to same recipient yielded full alignment with encoding passing as UTF-8 and no extra 'NextPart' added.
Sample of email sent from Outlook:
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1572285895; s=zoho; d=email.com; i=*** Email address is removed for privacy ***; h=From:To:References:In-Reply-To:Subject
ate:Message-ID:MIME-Version:Content-Type; l=2911; bh=55oF4546764h4g4676t57574+Vtr7xAyCI+9fEOOLbGjyfa0E52iy36tJ5PPlFg=; b=Wdn3LaXGjO+zhoTfy6i7kmyhgfcR2EGR6DTJX+LVldSDEmWTdTm4gIQH3tLIzyTVwLe89UfbnfHF c5FFA6RUBPi+kxJd5qWA/Ek51MBizguuIO1rxckZfNT31UDp0tipm1LZj32J5MEvUpV i2YndTwcRMGokvyfNckz/J0WNBxXyjyj6trhjyhnben0nDbV2W/X4=Received: from PC (12.345.67.89 [12.345.67.89]) by mx.zohomail.com with SMTPS id 1572285893097569.92580635065016; Mon, 28 Oct 2019 11:04:53 -0700
From: *** Email address is removed for privacy ***
To: <*** Email address is removed for privacy ***>
Subject: Outlook to Gmail
Date: Mon, 28 Oct 2019 14:04:51 -0400
Message-ID: <*** Email address is removed for privacy ***>
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="----=_NextPart_000_0091_01D58D98.AB7F9BF0"
X-Mailer: Microsoft Outlook 16.0
Thread-Index: AQMrjcYI76YKJTL13jlnlC+Yh/R+xaTEWLRw
Content-Language: en-us
X-ZohoMailClient: External
------=_NextPart_000_0091_01D58D98.AB7F9BF0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
From: *** Email address is removed for privacy *** <*** Email address is removed for privacy ***>
Sent: Monday, October 28, 2019 2:01 PM
To: *** Email address is removed for privacy *** <*** Email address is removed for privacy ***>
Subject: Outlook to Gmail
Testing testing testing
------=_NextPart_000_0091_01D58D98.AB7F9BF0
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
<html xmlns:v=3D"urn:schemas-microsoft-com:vml" xmlns
=3D"urn:schemas-micr=osoft-com
fficeffice" xmlns:w=3D"urn:schemas-microsoft-comffice:word" =xmlns:m=3D xmlns=3D"http:=
//www.w3.org/TR/REC-html40"><head><meta http-equiv=3DContent-Type content=
=3D"text/html; charset=3Dutf-8"><meta name=3DGenerator content=3D"Microsoft=
Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
=09{font-family:"Cambria Math";
=09panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
=09{font-family:Calibri;
=09panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
=09{margin:0in;
=09margin-bottom:.0001pt;
=09font-size:11.0pt;
=09font-family:"Calibri",sans-serif;}
................................................ *** Email address is removed for privacy ***' =
<*** Email address is removed for privacy ***><br><b>Subject:</b>Outlook to Gmail<o
></o=></p><p class=3DMsoNormal><o> </o></p><p class=3DMsoNormal>Testi=ng testing testing<o
></o></p></div></body></html>------=_NextPart_000_0091_01D58D98.AB7F9BF0--
This is happening across multiple Windows 10 systems running different versions of Outlook, and possibly Outlook on mobile (I have not yet investigated if this is indeed the cause for the failures on mobile) and Outlook.com. Outlook is the common link across all failures.
Is there a setting I need to add or change somewhere in the settings to stop Outlook from doing this? If not, what is the workaround here to use Outlook but still pass fully aligned email?
Please let me know, thanks.
Continue reading...