Email Standard.

Email Standard. 

I am trying to put them in writing below.

An Ideal Email ID should have 3 parts in representation, eg. User1@gmail.com

1.       Domain name (gmail.com)

2.       “@” symbol

3.       Valid user in the system (User1)

Always Email ID will be read from back to front, that is the domain name will be read first in the Email ID then everything else.  After Domain name ‘@’ symbol is expected and finally Username will be considered.

When I try to send an email from my machine using telnet session on 25 port, as below.

Date: Fri, 20 Jan 2012 15:23:43 +0530

From: User1@test.com

Message-Id: <201201200953.q0K9rhlj004368@Local.com>

To: Test-user@example.com

Subject: subject

Return-Path: <User1@test.com>

Received: from Local.com ([10.30.117.97])

        by mail.local.com (Switch-3.4.3/Switch-3.4.3) with ESMTP id q0K9s3DZ012502

        for <Test-user@example.com>; Fri, 20 Jan 2012 04:54:04 -0500

Received: from Local.com (localhost.localdomain [127.0.0.1])

        by Local.com (8.13.8/8.13.8) with ESMTP id q0K9rhv2004369

        for <Test-user@example.com>; Fri, 20 Jan 2012 15:23:43 +0530

Received: (from root@localhost)

        by Local.com (8.13.8/8.13.8/Submit) id q0K9rhlj004368

        for Test-user@example.com; Fri, 20 Jan 2012 15:23:43 +0530

The above example of email header info is modified to make it simple. When you read this header info which is generally analyzed by the email spam scanner you can find few odd things. Like the email says it’s from User1@example.com and the return path also reflect it, but in the header you can see that email is from root@localhost (in your case it will be logged in user wit ‘@’ and machine FQDN) by Local.com (machine name). Also you see the ‘from’ domain is test.com, but the origin machine or the source IP address is a different domain Local.com.

Here you see two odd stuff one the ‘from’ email address and the other is the Domain.

This above contradiction in email header info is what always suspected as spam.

 .

Many relay system or email servers are restricted relay and only few where open relay system.So when you send a email of this contradiction then your IP address would be blocked by the spam database.

When you try sending an email best practice is that create a email ID with your email system and have them as the envelope sender as well as return path of the email.