How to beat Hotmail/Live/Outlook and AOL spam filters? (custom dedicated mail server)

Question

I am trying to set up a mail server for my client's web app.

The CentOS/Postfix-based mail server runs on a dedicated VPS from DigitalCocean.

SPF record: check DKIM (openDKIM): check Clean dedicated IP: check Clean domain: check

GMail, Yahoo, Zoho Mail, GMX/mail.com, Yandex Mail - absolutely no problems, all emails get delivered to the Inbox.

However it goes to Junk when sending to AOL and Live/Outlook/Hotmail users. I tried all types of content: plain text emails with a few words, HTML-rich emails and everything in between. The issue seems to be not related to the email content.

Microsoft support does not help much since they basically our server seems to fine and there is something they don't know to trigger their SmartScreen security.

Any thoughts ?

Answer 1

I had similar problem a while ago, in my case with AOL and Yahoo. The background was, that because of a failing mail server we needed a new one quickly.

This new mailserver became available before the appropriate DNS entries, especially the reverse DNS entry, were propagated. Obviously this led to the mail server being blocked by those providers. So checking the reverse DNS entry today does not guarantee an error in the past didn't cause this.

Besides what I learned on this occasion is, that all of those providers don't seem to reevaluate banned mail servers. Once you are on the black list, you stay there for quite a long time. As our first mail server could luckily be restored, we could check from time to time what AOL and Yahoo would do with the new one (second MX). Mail were blocked for two months, despite the mail server being configured with DKIM etc. until we formally applied to be removed from the blacklist - which took another 2 days.

With AOL you should use the appropriate from for applying to be removed from their blacklist; suppose Hotmail has something similar.

Answer 2

Before sending email into MS account using a new server you should make sure you comply to all the ms outlook technical guidelines & policies like SNDS also all your email should authenticated using the spf & dkim signature. Here is an article in details: Policies, Practices, and Guidelines

Make sure to follow the can spam act guidelines.

Also you should know that even if you do all this stuff you will not be able to get into the inbox folder until you gain a good email reputations so you need to ask your subscribers to add your email to the whitelist

Besides All this unfinished task you should consider checking all black list database if they have anything against you

Here is a good example of a full black list check. The complete IP check for sending Mailservers
also try to delist you ip address from the Outlook.com Deliverability Support

I wish this could be helpful for you