0

I've noticed a couple of times now that I get Delivery Status Notification (Failure) emails for emails I've not sent. I'm worried that someone else is using my account to send spam but I'm at the limits of my knowledge on these kinds of things.

Here's my set up:

  • Google Apps on a personal domain
  • 2FA auth, 32 char password (not reused with any other account)
  • DKIM set up to authenticate outgoing emails

The above made me feel very confident that I didn't need to worry about emails. Google would handle the hard stuff and I'd set up the security to meet my risk appetite.

Here's an example of one the emails I've received:

Delivered-To: dropbox@williammayor.co.uk
Received: by 10.28.230.77 with SMTP id d74csp2527957wmh;
        Thu, 16 Feb 2017 05:56:46 -0800 (PST)
X-Received: by 10.28.51.205 with SMTP id z196mr12396419wmz.22.1487253406837;
        Thu, 16 Feb 2017 05:56:46 -0800 (PST)
Return-Path: <>
Received: from mail-wm0-x244.google.com (mail-wm0-x244.google.com. [2a00:1450:400c:c09::244])
        by mx.google.com with ESMTPS id z26si7277207wrz.96.2017.02.16.05.56.46
        for <dropbox@williammayor.co.uk>
        (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
        Thu, 16 Feb 2017 05:56:46 -0800 (PST)
Received-SPF: pass (google.com: best guess record for domain of postmaster@mail-wm0-x244.google.com designates 2a00:1450:400c:c09::244 as permitted sender) client-ip=2a00:1450:400c:c09::244;
Authentication-Results: mx.google.com;
       dkim=pass header.i=@googlemail.com;
       spf=pass (google.com: best guess record for domain of postmaster@mail-wm0-x244.google.com designates 2a00:1450:400c:c09::244 as permitted sender) smtp.helo=mail-wm0-x244.google.com;
       dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=googlemail.com
Received: by mail-wm0-x244.google.com with SMTP id r18so3245363wmd.3
        for <dropbox@williammayor.co.uk>; Thu, 16 Feb 2017 05:56:46 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=googlemail.com; s=20161025;
        h=from:to:auto-submitted:subject:references:in-reply-to:message-id
         :date;
        bh=mZaso4RaS6Rf+0QVb1hTu2CwYlfXSyEt+yTtW7hR8uk=;
        b=JZYDQJVNVPKjA4Vq876gSrhWhjsXaHpAMnMY+y5Z9XZb/e7wVS7rxnOPzLYM/gO6ic
         6J8e/E94h1Uk/Hgrzk9G+poYUcuESpe2R1sF7y2+XnMsd00gJfbnQb9rQQK/IGVlL/vi
         8XHDawTG8ndMH0r9h003UIRGrKpt8T5jx5bdSaB8nTSvS9aaeSABBviwCvKHZGoWYveR
         cDQjvmtLAwIFO5k+4p/g4JpsYlZ2ojEN6fAIARwiXD2rVnROjDRWUMvCvDUPAlkWOKs8
         On8Jvp8qm0cUA1Dw/yIxA2hkxwYzqn9jwMygqjUCxDjM3YNBuWlcAdk0GJdUJZC+MB/O
         mPww==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20161025;
        h=x-gm-message-state:from:to:auto-submitted:subject:references
         :in-reply-to:message-id:date;
        bh=mZaso4RaS6Rf+0QVb1hTu2CwYlfXSyEt+yTtW7hR8uk=;
        b=lNavoK0q1Ic3pUvUQTypuNIITK1HVvq9BaRO5ar5Qs7OUU9hXRgcUbZsu7LaHtj+9g
         W5W37mG/HrlpG7XubPE1kqzqoN/tweLAmugnbijBH0d5Kl8Qaw2gxyEvll8zlBGDcJ5e
         ybIeUvJLVyXLw2zP1IPlFcM3rmt/8DULsCZ0QNarGigUyTkNc8+tI7Um7OPE6jSPGmhg
         7HPBX6Qgjq33T2RJdv9V9FeL7eTlB6yTTIC60NDsWdzLGS2CEPw+wlF9iGpleNf+fsZk
         WqHd323ds91smc5QXLs+yaH98gIRU4dYBoCtqfs8axxncBbPkzlYx5tIseTBsL4oXiTQ
         KvIw==
X-Gm-Message-State: AMke39llod4HSPtWN0UbX5cUGczBpbi+v8wlvcKYXUWllEul0FQDOWx/SYOPpTkn/8iOdVJHu+tQUqoSHFlDxDcLdh/ba4/TXpKVCp4=
X-Received: by 10.28.194.5 with SMTP id s5mr1688371wmf.98.1487253406629;
        Thu, 16 Feb 2017 05:56:46 -0800 (PST)
Content-Type: multipart/report; boundary=001a114b06eefe38320548a62ae8; report-type=delivery-status
Return-Path: <>
Received: by 10.28.194.5 with SMTP id s5mr1816172wmf.98; Thu, 16 Feb 2017
 05:56:46 -0800 (PST)
From: Mail Delivery Subsystem <mailer-daemon@googlemail.com>
To: dropbox@williammayor.co.uk
Auto-Submitted: auto-replied
Subject: Delivery Status Notification (Failure)
References: <58A56946.2178.568202@dropbox.williammayor.co.uk>
In-Reply-To: <58A56946.2178.568202@dropbox.williammayor.co.uk>
Message-ID: <58a5af9e.05c21c0a.9a844.2280.GMRIR@mx.google.com>
Date: Thu, 16 Feb 2017 05:56:46 -0800 (PST)

--001a114b06eefe38320548a62ae8
Content-Type: multipart/related; boundary=001a114b06eefe38a60548a62ae9

--001a114b06eefe38a60548a62ae9
Content-Type: multipart/alternative; boundary=001a114b06eefe38aa0548a62aea

--001a114b06eefe38aa0548a62aea
Content-Type: text/plain; charset=UTF-8


** Address not found **

Your message wasn't delivered to th3801@gone.bristol.ac.uk because the address couldn't be found. Check for typos or unnecessary spaces and try again.

Learn more here: https://support.google.com/mail/?p=NoSuchUser

The response from the remote server was:
550 5.1.1 The email account that you tried to reach does not exist. Please try double-checking the recipient's email address for typos or unnecessary spaces. Learn more at https://support.google.com/mail/?p=NoSuchUser y128si668637wme.153 - gsmtp

--001a114b06eefe38aa0548a62aea
Content-Type: text/html; charset=UTF-8


<html>
<head>
<style>
* {
font-family:Roboto, "Helvetica Neue", Helvetica, Arial, sans-serif;
}
</style>
</head>
<body>
<table cellpadding="0" cellspacing="0" class="email-wrapper" style="padding-top:32px;background-color:#ffffff;"><tbody>
<tr><td>
<table cellpadding=0 cellspacing=0><tbody>
<tr><td style="max-width:560px;padding:24px 24px 32px;background-color:#fafafa;border:1px solid #e0e0e0;border-radius:2px">
<img style="padding:0 24px 16px 0;float:left" width=72 height=72 alt="Error Icon" src="cid:icon.png">
<table style="min-width:272px;padding-top:8px"><tbody>
<tr><td><h2 style="font-size:20px;color:#212121;font-weight:bold;margin:0">
Address not found
</h2></td></tr>
<tr><td style="padding-top:20px;color:#757575;font-size:16px;font-weight:normal;text-align:left">
Your message wasn't delivered to <a style='color:#212121;text-decoration:none'><b>th3801@gone.bristol.ac.uk</b></a> because the address couldn't be found. Check for typos or unnecessary spaces and try again.
</td></tr>
<tr><td style="padding-top:24px;color:#4285F4;font-size:14px;font-weight:bold;text-align:left">
<a style="text-decoration:none" href="https://support.google.com/mail/?p=NoSuchUser">LEARN MORE</a>
</td></tr>
</tbody></table>
</td></tr>
</tbody></table>
</td></tr>
<tr style="border:none;background-color:#fff;font-size:12.8px;width:90%">
<td align="left" style="padding:48px 10px">
The response from the remote server was:<br/>
<p style="font-family:monospace">
550 5.1.1 The email account that you tried to reach does not exist. Please try double-checking the recipient&#39;s email address for typos or unnecessary spaces. Learn more at https://support.google.com/mail/?p=NoSuchUser y128si668637wme.153 - gsmtp
</p>
</td>
</tr>
</tbody></table>
</body>
</html>

--001a114b06eefe38aa0548a62aea--
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--001a114b06eefe38a60548a62ae9--
--001a114b06eefe38320548a62ae8
Content-Type: message/delivery-status

Reporting-MTA: dns; googlemail.com
Received-From-MTA: dns; dropbox@williammayor.co.uk
Arrival-Date: Thu, 16 Feb 2017 05:56:46 -0800 (PST)
X-Original-Message-ID: <58A56946.2178.568202@dropbox.williammayor.co.uk>

Final-Recipient: rfc822; th3801@gone.bristol.ac.uk
Action: failed
Status: 5.1.1
Remote-MTA: dns; aspmx.l.google.com. (64.233.184.27, the server for the domain gone.bristol.ac.uk.)
Diagnostic-Code: smtp; 550-5.1.1 The email account that you tried to reach does not exist. Please try
 550-5.1.1 double-checking the recipient's email address for typos or
 550-5.1.1 unnecessary spaces. Learn more at
 550 5.1.1  https://support.google.com/mail/?p=NoSuchUser y128si668637wme.153 - gsmtp
Last-Attempt-Date: Thu, 16 Feb 2017 05:56:46 -0800 (PST)

--001a114b06eefe38320548a62ae8
Content-Type: message/global

X-Google-DKIM-Signature: v=3D1; a=3Drsa-sha256; c=3Drelaxed/relaxed;
        d=3D1e100.net; s=3D20161025;
        h=3Dx-gm-message-state:x-original-authentication-results:from:to:da=
te
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Ut
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X-Received: by 10.28.194.5 with SMTP id s5mr1688355wmf.98.1487253406479;
        Thu, 16 Feb 2017 05:56:46 -0800 (PST)
X-Received: by 10.28.194.5 with SMTP id s5mr1688348wmf.98.1487253406319;
        Thu, 16 Feb 2017 05:56:46 -0800 (PST)
Return-Path: <dropbox@williammayor.co.uk>
Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com. [209.85.=
128.197])
        by mx.google.com with ESMTPS id f200si612772wme.108.2017.02.16.05.5=
6.46
        for <th3801@my.bristol.ac.uk>
        (version=3DTLS1_2 cipher=3DECDHE-RSA-AES128-GCM-SHA256 bits=3D128/1=
28);
        Thu, 16 Feb 2017 05:56:46 -0800 (PST)
Received-SPF: neutral (google.com: 209.85.128.197 is neither permitted nor =
denied by best guess record for domain of dropbox@williammayor.co.uk) clien=
t-ip=3D209.85.128.197;
Authentication-Results: mx.google.com;
       spf=3Dneutral (google.com: 209.85.128.197 is neither permitted nor d=
enied by best guess record for domain of dropbox@williammayor.co.uk) smtp.m=
ailfrom=3Ddropbox@williammayor.co.uk
Received: by mail-wr0-f197.google.com with SMTP id y7so3180714wrc.7
        for <th3801@my.bristol.ac.uk>; Thu, 16 Feb 2017 05:56:46 -0800 (PST=
)
X-Original-Authentication-Results: mx.google.com;       spf=3Dneutral (goog=
le.com: 190.67.150.7 is neither permitted nor denied by best guess record f=
or domain of dropbox@williammayor.co.uk) smtp.mailfrom=3Ddropbox@williammay=
or.co.uk
X-Received: by 10.223.136.205 with SMTP id g13mr2341030wrg.56.1487253406058=
;
        Thu, 16 Feb 2017 05:56:46 -0800 (PST)
X-Received: by 10.223.136.205 with SMTP id g13mr2341026wrg.56.1487253405942=
;
        Thu, 16 Feb 2017 05:56:45 -0800 (PST)
Return-Path: <dropbox@williammayor.co.uk>
Received: from [190.67.150.7] ([190.67.150.7])
        by mx.google.com with ESMTP id 6si9416331wrr.155.2017.02.16.05.56.4=
3
        for <th3801@bris.ac.uk>;
        Thu, 16 Feb 2017 05:56:45 -0800 (PST)
Received-SPF: neutral (google.com: 190.67.150.7 is neither permitted nor de=
nied by best guess record for domain of dropbox@williammayor.co.uk) client-=
ip=3D190.67.150.7;
From: <dropbox@williammayor.co.uk>
To: <th3801@bris.ac.uk>
Date: 16 Feb 2017 02:22:38 -0600
MIME-Version: 1.0
Subject: Local representation needed for the International Company
Message-ID: <58A56946.2178.568202@dropbox.williammayor.co.uk>
Priority: normal
X-mailer: Pegasus Mail for Windows (4.61)
Content-type: multipart/alternative; boundary=3D"Alt-Boundary-29754.9314526=
"

Dear th3801,

We are looking for employees working remotely.

My name is Major, I am the personnel manager of a large International compa=
ny.
Most of the work you can do from home, that is, at a distance.

Salary is $2200-$5400.

If you are interested in this offer, please visit=20
Our Site

d_healthBest regards!
--001a114b06eefe38320548a62ae8--

As you can see the email seems to be sent from dropbox@williammayor.co.uk, that's not a real email address. I have a wildcard alias set up on my domain so I can sign up for accounts without revealing my actual address. Someone seems to have found my dropbox one?

The original email is some kind of spam/fraud about remote working. Sent to a Bristol University account.

My thoughts are:

  1. Someone is sending emails and spoofing my email address
  2. Someone is trying to trick me into thinking they're doing that

What's going on? How can I stop it? What mistakes have I made here? I rely on Google Apps to take care of the tricky parts and I'm concerned that I've missed something important (especially seeing as I manage other IT infrastructures using Google Apps).

Thanks!

  • 1
    spf configured? – yagmoth555 Feb 20 '17 at 11:54
  • Possible duplicate of Stop spoof emails in Google Apps – pete Feb 20 '17 at 21:58
  • Huh! No SPF for the main domain. I've added that now, thanks yagmoth555. The other answer suggests that this might not be enough but we'll see. Thanks! – WilliamMayor Feb 21 '17 at 13:25

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