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

Question

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 :

Received-SPF: pass (google.com: domain of noreply@monstermmorpg.com designates 85.17.154.139 as permitted sender) client-ip=85.17.154.139;
MIME-Version: 1.0
From: "MonsterMMORPG"
 <noreply@monstermmorpg.com>
To: mypersonalemail@gmail.com
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
Message-ID: <XCPV002ednHM3SOlbpH0004e7c7@noreply.monstermmorpg.com>

hotmail headers

MIME-Version: 1.0
From: "MonsterMMORPG"
 <noreply@monstermmorpg.com>
To: mypersonalemail@hotmail.com
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
Message-ID: <XCPV002DreBBsQwY6YH0004e7c9@noreply.monstermmorpg.com>

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("noreply@monstermmorpg.com", 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

score 3 · Accepted Answer · answered Mar 10 '12 at 16:31

3

You get one Received header for every SMTP server that handles your message. In your case you get one when your application connects via SMTP to localhost and injects the message for the first time, and a second header when that IIS system passes the email to the server for HotMail or GMail.

This is absolutely normal, and expected.

answered Mar 10 '12 at 16:31

Daniel Pittman

5,692
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I checked other emails i have received and they have only single header. Aren't there any way to remove second header which displays localhost ip. Thank you very much for the answer. – MonsterMMORPG Mar 10 '12 at 16:34
Do you mean other emails from your own software, or from third parties? The most common way to avoid the "Received from 127.0.0.1" header is to use something other than SMTP to submit the initial email. Letting the world know that you have a loopback interface isn't a big deal, though, since every computer everywhere has a 127.0.0.1 address... – Daniel Pittman Mar 10 '12 at 16:40
Well i have fear that it would increase dropping spam box chance. So you are saying it won't have any affect? Also i mean third parties not my softwares. – MonsterMMORPG Mar 10 '12 at 17:05
I can't say authoritatively if it will read like spam, but you would hardly be the first service in the world to end up with a local received header like that. – Daniel Pittman Mar 10 '12 at 17:09

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

1 Answers1