Hetzner - DokuWiki

Microsoft Blacklist/en


Microsoft Blacklist

Microsoft maintains their own internal blacklist. This blacklist is used to check all emails going to hotmail.com, live.com, outlook.com and msn.com addresses, as well as many custom domain names that clients have setup using Microsoft email services.

Any IPs listed on the Spamhaus blacklist are also blacklisted by Microsoft. The rest of the blacklisted IPs are based on Microsoft's own criteria. These listings are not very transparent, and unfortunately include a large amount of false-positives.

If a particular IP is listed, then any emails from that IP to Microsoft email accounts will be met with the following error message:

550 5.7.1 Unfortunately, messages from [x.x.x.x] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors.

If you receive this error message when sending emails from a server you have with us, then please don’t worry. More often than not the IP isn’t listed on any (other) blacklists; it is only Microsoft that is causing issues. Thankfully, Microsoft provides a form that you can fill out to delist the IP.

Before you request a delisting though, please ensure your emails comply with the Microsoft policies, practices and guidelines found on their website: http://mail.live.com/mail/policies.aspx


You can find the official form for delisting IP(s) here: http://go.microsoft.com/fwlink/?LinkID=614866&clcid

Alternative Link: https://support.microsoft.com/en-us/getsupport?oaspworkflow=start_1.0.0.0&wfname=capsub&productkey=edfsmsbl3

Once you have filled the form out, you should get an auto-reply within an hour, sometimes even within a few minutes, confirming they have gotten your request.

After that, and usually within 12 hours, Microsoft support will answer. This response will show that the IP has either been delisted (Microsoft calls this “conditionally mitigated”) or that the IP is not eligible for delisting. If the IP does not get delisted, please reply to the email and ask Microsoft why, and ask them to please check this again. Usually they will then respond within 24 hours, and manually delist the IP.

In those rare cases where they still won’t delist the IP, please contact our support team by sending a request via the Robot administration interface.

Microsoft Programs

For advanced users, it can be helpful to join two free programs that Microsoft offers: the Smart Network Data Services (SNDS) and the Junk Email Reporting program (JMRP).

Please note that neither the SNDS nor the JMRP allow you to delist your IP; they simply provide detailed information about the traffic on your sending IP, the sending IP reputation with Microsoft, and the user complaint rates.

As Microsoft says, there is no silver bullet to maintaining or improving good IP reputation, but these programs help you proactively manage your email eco-system to help ensure better deliverability to Microsoft users.


This program allows you to monitor the "health" and reputation of your registered IPs by providing data about traffic such as mail volume and complaint rates seen originating from your IPs.

To register, please visit: https://sendersupport.olc.protection.outlook.com/snds/

Important notes:

  • We will only verify a registration if the name used in the SNDS is the same as the name we have on file in the Robot administration interface.
  • Please send authorization requests to info@hetzner.de (or alternatively abuse@hetzner.de).
  • The SNDS does not allow you to delist your IP.


When a Microsoft user marks an email as "junk", senders enrolled in this program get a copy of the mail forwarded to the email address of their choice. It allows you to see which emails are being marked as junk and to identify email traffic you did not intend to send.

To join, please visit: https://sendersupport.olc.protection.outlook.com/snds/JMRP.aspx?wa=wsignin1.0

© 2019. Hetzner Online GmbH. Alle Rechte vorbehalten.