Google marks seemingly perfect emails as spam [closed]

Question

First post, have found many answers here, so hopes are high.

The problem: Google marks seemingly correctly formatted emails from my apache/postfix server as spam. Sample email as follows;

(I have replaced my domain with mydomain.com.au and the IP with a pretend IP)

Delivered-To: my.email@gmail.com
Received: by 10.150.216.21 with SMTP id o21cs22383ybg;
        Fri, 26 Feb 2010 23:11:55 -0800 (PST)
Received: by 10.231.152.75 with SMTP id f11mr1470919ibw.50.1267254715619;
        Fri, 26 Feb 2010 23:11:55 -0800 (PST)
Return-Path: <apache@mydomain.com.au>
Received: from mydomain.com.au (mydomain.com.au [80.107.158.80])
        by mx.google.com with ESMTP id 29si1651619iwn.31.2010.02.26.23.11.54;
        Fri, 26 Feb 2010 23:11:55 -0800 (PST)
Received-SPF: pass (google.com: domain of apache@mydomain.com.au designates 80.107.158.80 as permitted sender) client-ip=80.107.158.80;
Authentication-Results: mx.google.com; spf=pass (google.com: domain of apache@mydomain.com.au designates 80.107.158.80 as permitted sender) smtp.mail=apache@mydomain.com.au
Received: by mydomain.com.au (Postfix, from userid 48)
    id ACB735030340; Sat, 27 Feb 2010 18:11:53 +1100 (EST)
To: my.email@gmail.com
Subject: Quote for David Brent (00125512123)
From: quotes@mydomain.com.au
Reply-To: quotes@mydomain.com.au
X-Mailer: PHP/5.2.10
Message-Id: <20100227071153.ACB735030340@mydomain.com.au>
Date: Sat, 27 Feb 2010 18:11:53 +1100 (EST)

Name: David Brent

Mobile: 00125512123

Phone:

Email: my.email@gmail.com

Date: 2010-20-21

Time: 21:00

Location: Syd

Eventype: Musicians

Message: Yep, this should work!!!!

how did you hear about us: Newspaper

• I have tried sending it to non-google emails, and they arrive fine.
• I have tried posting to several different google accounts, all end up as spam.
• Mydomain.com.au uses Google Apps as email provider.
• I have added "v=spf1 a mx ~all" as TXT in my NS.
• I used http://remote.12dt.com/ to check reverse DNS and the IP seems to be resolving back to the domain name just fine.

The headers seem fine, and the SPF look up seems to pass (?).. Any ideas?

Kind regards

Answer 1

It is not that simple. If all you had to do was provide SPF and an RFC-compliant message, every spammer in the world could get past such a filter.

This could be due to sender reputation, i.e. apache@mydomain.com.au may have sent spam messages before, or 80.107.158.80 may be previously unknown to Google. Google knows that a new sender suddenly popping up from a previously unknown IP is possibly a hacked server or part of a botnet.