smtp-headers questions - Page 1

Peter Saunders

Asked: 2024-06-30 01:34:35 +0800 CST

SMTP Header confusion - Delivered-To: and To: are different

6

This is bugging me. I've looked at this thread: How can the `to:` and `delivered-to:` fields in an email i received be different?, but I'm still confused, so hope someone can shed some more light on this.

I received an email with the following header. I'm wondering why my email address ([email protected]) does not appear in the To: line, but only in the Delivered-To: line. Also has the same email been delivered to my colleague ([email protected]) and does the header in his email show mycolleague in the Delivered-To: line and myemail in the To: line?

(All the bits I've anonymised are in italics.)

Date: Fri, 21 Jun 2024 16:44:55 +0800
From: ip <[email protected]>
To: _mycolleague_ <[email protected]_>
Reply-To: robert <[email protected]>, 
    trademark <[email protected]>
Subject: RE:  _mydomain_-Domains updated and renewal (Urgent to Principal/CEO)
Disposition-Notification-To: ip <[email protected]>
Mime-Version: 1.0
Message-ID: <[email protected]>
Content-Type: text/plain;
    charset="gb2312"
Content-Transfer-Encoding: base64

lordbyron

Asked: 2016-05-30 15:47:04 +0800 CST

Why don't my domain's messages to a google group get their headers rewritten so DMARC can pass?

10

Whenever my domain sends a message to a google group on another domain the DMARC alignment fails. This is true for all my approved senders, even using Gmail in my domain. It seems to be because the Return-Path (Envelope From) header is replaced by the receiving group's bounce address, but the From header remains as my domain, which is incorrect.

For example, I send mail from Gmail in my domain, [email protected], to a group in your domain, [email protected]. If you look at the headers of the message you receive, you see:

BAD

Return-Path: <[email protected]>
Authentication-Results: mx.google.com;
   dkim=pass [email protected];
   spf=pass (google.com: domain of [email protected] designates 2607:f8b0:400d:c04::246 as permitted sender)
smtp.mailfrom=your-group+bncBCA5XFGRYQLCBEHHVS5AKGQED3J2I7I@yourdomain.com;
   dmarc=fail (p=NONE dis=NONE) header.from=mydomain.com
From: Chris <[email protected]>

X-Original-Sender: [email protected]
X-Original-Authentication-Results: mx.google.com;       dkim=pass
 [email protected];       spf=pass (google.com: domain of [email protected]
 designates 2607:f8b0:400c:c05::233 as permitted sender)
[email protected];
       dmarc=pass (p=NONE dis=NONE) header.from=mydomain.com

DMARC fails because of bad alignment between the From domain (mydomain) and the DKIM and SPF domains (yourdomain). However, when you, a properly configured GApps user, send mail from Gmail to a group at mydomain, the headers are different.

GOOD

Return-Path: <[email protected]>
Authentication-Results: mx.google.com;
       dkim=pass [email protected];
       spf=pass (google.com: domain of [email protected] designates 2607:f8b0:4001:c0b::247 as permitted sender) smtp.mailfrom=my-group+bncBCGJ3NF22YBRBTXIVS1RKGQEIWR5E6Q@mydomain.com;
   dmarc=pass (p=NONE dis=NONE) header.from=mydomain.com
From: "'You' via my-group" <my-group@ mydomain.com>

Note the different form of the From header - the original sender has been replaced by my own group. There is also a pair of X-Original headers as above that have the same form (just reversed), so I'm not pasting them.

So the question is, how do I configure my domain, gapps, dns, mx, or whatever, so that Google Groups that receive my messages will correctly replace the From header with "via [email protected] ?"

Mail from my domain to users at other domains work fine - DMARC passes because SPF and DKIM are good and the Return-Path still says @mydomain. I have read articles about why the "via you-group" is necessary - I'm ok with that. I'm trying to figure why my messages to groups are not getting treated that way.

Seems to be similar to: How to prevent emails from my domain through mailing lists to be rejected due to DMARC Different because google groups are definitely compatible with DMARC - other people don't have this problem.

Update: I found this article which says google groups only rewrites the sender when the DMARC policy is strict (p=reject). That seems like a terrible idea since the whole point of starting with p=none is to gain confidence that your mail will get delivered when you up the policy, but if true then it may explain my issue. Can anyone confirm? http://www.spamresource.com/2014/04/google-groups-rewriting-from-addresses.html

MonsterMMORPG

Asked: 2012-03-11 08:28:51 +0800 CST

2 Received from header at IIS SMTP email send via C# application

3

I am using windows server 2008 r2 and IIS 7.5 normally. I am using IIS 6 smpt server to send emails. Right now when i send email via my C# application i am seeing 2 received from headers. What might be the cause of this ?

Displaying both gmail and hotmail headers

gmail :

Delivered-To: [email protected]
Received: by 10.112.29.167 with SMTP id l7csp43703lbh;
        Sat, 10 Mar 2012 08:16:29 -0800 (PST)
Received: by 10.14.127.12 with SMTP id c12mr1026618eei.19.1331396188791;
        Sat, 10 Mar 2012 08:16:28 -0800 (PST)
Return-Path: <[email protected]>
Received: from noreply.monstermmorpg.com (noreply.monstermmorpg.com. [85.17.154.139])
        by mx.google.com with ESMTP id f41si4528441eeo.146.2012.03.10.08.16.27;
        Sat, 10 Mar 2012 08:16:28 -0800 (PST)
Received-SPF: pass (google.com: domain of [email protected] designates 85.17.154.139 as permitted sender) client-ip=85.17.154.139;
Authentication-Results: mx.google.com; spf=pass (google.com: domain of [email protected] designates 85.17.154.139 as permitted sender) [email protected]
Received: from XCPV002 ([127.0.0.1]) by noreply.monstermmorpg.com with Microsoft SMTPSVC(7.5.7601.17514);
     Sat, 10 Mar 2012 16:16:28 +0000
MIME-Version: 1.0
From: "MonsterMMORPG"
 <[email protected]>
To: [email protected]
Date: 10 Mar 2012 16:16:28 +0000
Subject: =?utf-8?B?UG9rZW1vbkNyYWZ0IGRhaGEga2FsaXRlbGkgYmlyIG95dW4g?=
 =?utf-8?B?b2xhcmFrIGdlcmkgZMO2bmTDvC4gRXNraSBoZXNhYsSxbsSxeiBkdXJ1?=
 =?utf-8?B?eW9yLg==?=
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: base64
Return-Path: [email protected]
Message-ID: <[email protected]>
X-OriginalArrivalTime: 10 Mar 2012 16:16:28.0941 (UTC) FILETIME=[26372BD0:01CCFED9]

hotmail headers

x-store-info:sbevkl2QZR7OXo7WID5ZcaZ0jeT0hTF6w5JqyzrMGIIJ4/L/t2gj2cA4gOeWpl7k+VkJUhAu0L19pcdx17/6zH+umIRUQcxNC7a6JMdOu4uk+atrpASsFAd6JPSp2WMA
Authentication-Results: hotmail.com; sender-id=temperror (sender IP is 85.17.154.139) [email protected]; dkim=none header.d=monstermmorpg.com; x-hmca=none
X-Message-Status: n:0:n
X-SID-PRA: MonsterMMORPG <[email protected]>
X-DKIM-Result: None
X-AUTH-Result: NONE
X-Message-Delivery: Vj0xLjE7dXM9MDtsPTA7YT0xO0Q9MTtHRD0xO1NDTD0w
X-Message-Info: NhFq/7gR1vQcnWpWXvTdSPoVLSrfQUf9NNYiD+nue1hb767bbTKXz+tuMD66iU4vKsnCmrISnMcViv7BRc8FinIdJij0qRdzfb9MQFyl8Qnq2jH2yHHz6W3BUjjFUEclGZIdpMuV4EQ=
Received: from noreply.monstermmorpg.com ([85.17.154.139]) by BAY0-MC3-F1.Bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4900);
     Sat, 10 Mar 2012 08:20:03 -0800
Received: from XCPV002 ([127.0.0.1]) by noreply.monstermmorpg.com with Microsoft SMTPSVC(7.5.7601.17514);
     Sat, 10 Mar 2012 16:20:03 +0000
MIME-Version: 1.0
From: "MonsterMMORPG"
 <[email protected]>
To: [email protected]
Date: 10 Mar 2012 16:20:03 +0000
Subject: =?utf-8?B?UG9rZW1vbkNyYWZ0IGRhaGEga2FsaXRlbGkgYmlyIG95dW4g?=
 =?utf-8?B?b2xhcmFrIGdlcmkgZMO2bmTDvC4gRXNraSBoZXNhYsSxbsSxeiBkdXJ1?=
 =?utf-8?B?eW9yLg==?=
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: base64
Return-Path: [email protected]
Message-ID: <[email protected]>
X-OriginalArrivalTime: 10 Mar 2012 16:20:03.0608 (UTC) FILETIME=[A62AC180:01CCFED9]

If you check you will see that there are 2 received from headers. Let me also show how do i send email and my smtp server config

This is how i send email C#

            MailMessage mail = new MailMessage();
            mail.To.Add(srEmail);
            mail.From = new MailAddress("[email protected]", srSender);
            mail.Subject = srEmailTitle;
            mail.Body = srEmailBody;
            mail.IsBodyHtml = true;
            mail.SubjectEncoding = System.Text.Encoding.UTF8;
            mail.BodyEncoding = System.Text.Encoding.UTF8;
            SmtpClient smtp = new SmtpClient();
            smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
            smtp.UseDefaultCredentials = true;
            smtp.Host = "127.0.0.1";
            smtp.Port = 25;
            smtp.Send(mail);

This is IIS server config

enter image description here

Thanks a lot for the help

Andreas

Asked: 2011-11-08 09:06:03 +0800 CST

With valid SPF my mail header becomes huge -> high spamassasin score

5

I have a dedicated server with a survey system running on a subdomain. The parent domain is hosted on another server. I send email via google apps.

Reverse DNS is correct.

Without SPF og DKIM, the very smart '[email protected]' returns a spamassasin score of ca. 0.

But with a passing SPF record and this summary

SPF check:          pass
DomainKeys check:   neutral
DKIM check:         neutral
Sender-ID check:    pass
SpamAssassin check: ham

I get a quite high spamassasin score of ca. 3 - due to the header being very big:

pts rule name              description
---- ---------------------- --------------------------------------------------
3.1 SINGLE_HEADER_2K       A single header contains 2K-3K characters
-0.7 RCVD_IN_DNSWL_LOW      RBL: Sender listed at http://www.dnswl.org/, low
                       trust

So my question is: It seems from this that I should delete the spf record? since a large header is deemed worse then a valid spf?

Or is it my spf which is wrong?

v=spf1 a mx ptr ip4:xxx.xx.xxx.xx mx include:_spf.google.com ip4:yy.yy.yy.yyy ~all

xxx IP is for the server with the tld yyy IP is the server where the subdomain is hosted.

Below a part of the header:

----------------------------------------------------------
SPF check details:
----------------------------------------------------------
Result:         pass
ID(s) verified: [email protected]
DNS record(s):
mydomain.dk. SPF (no records)
mydomain.dk. 400 IN TXT "v=spf1 a mx ptr ip4:xxx.xx.xxx.xx mx include:_spf.google.com ip4:yy.yy.yy.yyy ~all"
mydomain.dk. 360 IN A xxx.xx.xxx.xx
mydomain.dk. 41895 IN MX 10 aspmx.l.google.com.
mydomain.dk. 41895 IN MX 20 alt2.aspmx.l.google.com.
mydomain.dk. 41895 IN MX 20 alt1.aspmx.l.google.com.
mydomain.dk. 41895 IN MX 30 aspmx2.googlemail.com.
mydomain.dk. 41895 IN MX 30 aspmx3.googlemail.com.
mydomain.dk. 41895 IN MX 30 aspmx4.googlemail.com.
mydomain.dk. 41895 IN MX 30 aspmx5.googlemail.com.
aspmx.l.google.com. 217 IN A 74.125.115.27
alt2.aspmx.l.google.com. 204 IN A 209.85.229.27
alt1.aspmx.l.google.com. 248 IN A 209.85.229.26
aspmx2.googlemail.com. 1036 IN A 74.125.43.27
aspmx3.googlemail.com. 1658 IN A 74.125.127.27
aspmx4.googlemail.com. 863 IN A 209.85.229.27
aspmx5.googlemail.com. 921 IN A 74.125.157.27
174.160.85.209.in-addr.arpa. 86400 IN PTR mail-gy0-f174.google.com.
mail-gy0-f174.google.com. 86400 IN A 209.85.160.174
mydomain.dk. 41895 IN MX 10 aspmx.l.google.com.
mydomain.dk. 41895 IN MX 20 alt2.aspmx.l.google.com.
mydomain.dk. 41895 IN MX 20 alt1.aspmx.l.google.com.
mydomain.dk. 41895 IN MX 30 aspmx2.googlemail.com.
mydomain.dk. 41895 IN MX 30 aspmx4.googlemail.com.
mydomain.dk. 41895 IN MX 30 aspmx5.googlemail.com.
mydomain.dk. 41895 IN MX 30 aspmx3.googlemail.com.
aspmx.l.google.com. 217 IN A 74.125.115.27
alt2.aspmx.l.google.com. 204 IN A 209.85.229.27
alt1.aspmx.l.google.com. 248 IN A 209.85.229.26
aspmx2.googlemail.com. 1036 IN A 74.125.43.27
aspmx4.googlemail.com. 863 IN A 209.85.229.27
aspmx5.googlemail.com. 921 IN A 74.125.157.27
aspmx3.googlemail.com. 1658 IN A 74.125.127.27
_spf.google.com. SPF (no records)
_spf.google.com. 206 IN TXT "v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ip4:173.194.0.0/16 ?all"

Again I have crossed out my own IP's and the rest i guess is googles?

What should I do now? Should I delete the spf record, or can I change it somehow to get a smalle header, that still works?

Martijn Heemels

Asked: 2011-06-15 23:05:21 +0800 CST

Prepend X-header to all relayed messages in Postfix

5

I've got several production servers running a LAMP stack. They each have a local Postfix server catching any mail from the system and from PHP, and relaying it via a smarthost (the SendGrid SMTP service).

I'd like to add a custom header to every outgoing message sent to the smarthost. This allows me to filter statistics per server in SendGrid. Something like:

X-SMTPAPI: {"category": "www1"}

The Postfix docs mention using the PREPEND action in a Postfix 'access' table. So, I added the following line to /etc/postfix/access:

PREPEND X-SMTPAPI: {"category": "www1"}

and hashed the access file with postmap.

However, I have no idea how to use the map. Something like the following doesn't work:

smtp_client_restrictions = check_client_access hash:/etc/postfix/access

How do I make Postfix prepend this header?

SMTP Header confusion - Delivered-To: and To: are different

Why don't my domain's messages to a google group get their headers rewritten so DMARC can pass?

2 Received from header at IIS SMTP email send via C# application

With valid SPF my mail header becomes huge -> high spamassasin score

Prepend X-header to all relayed messages in Postfix

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Questions[smtp-headers](server)