Why Does hotmail still reject my emails?

I have a very strange problem with my emails being marked as spam by hotmail.
I just have configured Postfix + Dovecot on my server and all works perfectly. I can Send/Receive emails. I only have problems with hotmail accounts, I do not understand the reason, because I also configured:

• SPF
• DKIM
• rDNS
• My IP is not listed in any backlist, I used: mxtoolbox.com

Checking the headers I see that SPF and DKIM pass correctly. I have no problem with GMAIL, YAHOO, and other, but hotmail seems very strict.

The only problem I think... could be that my IP had no email traffic yet. I've sent very few emails to hotmail.

So, if postfix has no problem, what do I have to do to send emails to hotmail correctly? Because if the only reason is that I had no email traffic yet it means that my first newsletters will be tag as SPAM without no reason.

Advice?

(An example of email received as SPAM is below)

HEADERS:

x-store-info:4r51+eLowCe79NzwdU2kRwMf1FfZT+JrxVyutn/pLjoZiDggbl3J7aHGkQoNPd8ZB9iY77nKNhzoKkbFqj2wPQ4Ha91HUDyzG+BsQ2lzn+x/xsXGuDBWhAPIPgrYY3dCiWYILdpiCyM=
Authentication-Results: hotmail.com; sender-id=pass (sender IP is 66.85.140.94) [email protected]; dkim=pass header.d=example.net; x-hmca=pass
X-SID-PRA: [email protected]
X-SID-Result: Pass
X-DKIM-Result: Pass
X-AUTH-Result: PASS
X-Message-Status: n:n
X-Message-Delivery: Vj0xLjE7dXM9MDtsPTA7YT0wO0Q9MjtHRD0yO1NDTD00
X-Message-Info: M98loaK0Lo1j8FOgXol8UFVrP26QMSvVTQXke21+QxXu+DJ5ttCh6cM/eFA+HRgTBFdz52wvmszvfgxVXBCfExvqqIFxcJKaFap8dwTFrYmSiOTK6J40vAbrC+QeYPnMG9Hntes6IFH9T95bydckDQ==
Received: from mail.example.net ([66.85.140.94]) by SNT0-MC3-F15.Snt0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4900);
     Sun, 30 Sep 2012 14:13:33 -0700
Received: from [192.168.1.2] (2-231-150-154.ip207.fastwebnet.it [2.231.150.154])
    by mail.example.net (Postfix) with ESMTPA id DD0A3401D9
    for <[email protected]>; Sun, 30 Sep 2012 21:13:31 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=example.net;
    s=mail; t=1349039612;
    bh=qCXqeVFYopgNSxSiqL3ANA5CfkeFw8AlGDFYh/ruUlg=;
    h=Date:From:To:Subject;
    b=NIYcYZJ4YitQHGus2ZQV4ErzN+hvFoDWi+M53eJXZSx3o0VamoA8PODMEZlWqvG29
     aYQK8DVW140wZ1tmHCvNCIe+KF/FVmRkxtD2aWGVK5OhVNuFv6ldRE7VUDhlPfOvaZ
     uUqp1QopHJsg8pGDTeifigb58xTa2V4AOac6WY4c=
Message-ID: <[email protected]>
Date: Sun, 30 Sep 2012 23:13:30 +0200
From: Aziende Mandanti <[email protected]>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1
MIME-Version: 1.0
To: [email protected]
Subject: Registrazione avvenuta con successo
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Content-Transfer-Encoding: 8bit
Return-Path: [email protected]
X-OriginalArrivalTime: 30 Sep 2012 21:13:33.0410 (UTC) FILETIME=[72B24C20:01CD9F50]

Gentile Damiano,
la registrazione è avvenuta correttamente.
Saluti

example.net

The IP you see in the headers is correct, I only obfuscated the email addresses

Solution 1:

Checking the headers I see that SPF and DKIM pass correctly. I have no problem with GMAIL, YAHOO, and other, but hotmail seems very strict.

This is correct. Hotmail / outlook.com are insanely strict for .. really no sensible reason at all. You have checked the obvious things:

• SPF
• DKIM
• reverse DNS
• My IP is not listed in any backlist, I used: mxtoolbox.com

The only thing left to do is manually file a request with Microsoft to get your URL listed in their safe senders. I really wish I was kidding, but even after triple checking all our mail settings (same as your above bulleted list), testing successfully on every other mail provider under the sun, etcetera, we had to file a manual Hotmail inclusion request in 2010 before email from Stack Overflow, Super User, Server Fault et al would arrive to Hotmail / outlook.com users.

As you can see on Microsoft's Postmaster Troubleshooting page:

IPs not previously used to send email typically don’t have any reputation built up in our systems. As a result, emails from new IPs are more likely to experience deliverability issues. Once the IP has built a reputation for not sending spam, Outlook will typically allow for a better email delivery experience.

The Improving E-mail Deliverability into Windows Live Hotmail (pdf) document describes this troubleshooting for the "Your e-mail is being delivered to the Junk e-mail Folder" scenario:

• Too many recipients reported your previous e-mails as spam
• Too much of your mail is sent to invalid or inactive e-mail addresses
• Your SenderID record is incorrect or missing

None of which applies here to a new mailer anyway, and SenderID / SPF was already checked as valid.

So this begs the question, how exactly do you get positive email reputation when all your emails go into the spam folder on day zero?

The only way we could get it to work is to .. file for a manual inclusion request.

If your email complies with our policies and guidelines and you are still experiencing email delivery problems that are not addressed in the FAQ below, click here to contact support.

Once I did this I got a deliverability email which looks automated, but that's good in this case:

This mail is to confirm that the IP(s) listed below are being investigated by our automated system.

Please note that your ticket number is in the subject line of this mail.

192.168.1.1

Note: Errors are unlikely, however, if an error is indicated, please resubmit the specific IP or IP range.

Thank you,
Hotmail Deliverability Support Service

Additionally, Microsoft recommends that

in addition, to adding your new IPs to existing Sender ID records, don’t forget to update your Junk Email Reporting Program (JMRP) account with the new IPs as well. To update or set up a JMRP account, click here.

Solution 2:

I don't see anything wrong with your headers, or anything obvious that you're doing wrong, but I would like to point out that, yes, hotmail (as well as live and msn and outlook webmail) are very strict, and tend to classify a lot of mass-mailings as spam, even when they shouldn't be.

A Google search on hotmail emails marked as spam turns up scores of similar questions with people having problems sending newsletters, registration confirmation emails and so on to Microsoft webmail domains, so it's probably nothing that you're doing wrong, but you need to put a lot of work into getting a mass mailing or automated mailing to pass through the spam filters Microsoft has in place for their webmail.

The place I'd start looking for "what to do next" would be the Microsoft webmail postmaster policies, practices and guidelines page.

They have 5 major guidelines you should make sure you're in compliance with (including American legislation you might not be aware of, and yes, it applies even to hotmail.it), some free reuptation management tools you might want to look at, as well as a way to contact "Hotmail Deliverability Support" if you're still having problems after complying with their guidelines.

Solution 3:

I suspect the problem here is a new ip has gone from sending low volumes of mail to high in a short space of time

https://senderscore.org/lookup.php?lookup=66.85.140.94&ipLookup=Go

Hotmail and others use return path reputation quite heavily

It's also worth signing up for SNDS at hotmail (presuming you haven't already)