If your emails cannot be delivered or sent to recipients using MSN or Windows Live Hotmail service, chance is the server which is sending the email messages may have been banned or blacklisted due to suspicion of sending spam. When a Windows Live Hotmail or MSN blocks or blacklists a host, all the mails originated from the IP address will get blocked, and returned or bounced with various error messages.

The typical bounced email messages contains the following error messages:

host mx1.hotmail.com[] said: 550 SC-001 Mail rejected by Windows Live Hotmail for policy reasons. Reasons for rejection may be related to content with spam-like characteristics or IP/domain reputation. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help.

host mx4.hotmail.com[] said: 550 SC-004 Mail rejected by Windows Live Hotmail for policy reasons. A block has been placed against your IP address because we have received complaints concerning mail coming from that IP address. We recommend enrolling in our Junk Email Reporting Program (JMRP), a free program intended to help senders remove unwanted recipients from their email list. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

There may be more SMTP reject error codes that are used by Windows Live Hotmail servers as listed on this page.

When a email host or server is in Windows Live or MSN Hotmail blacklist, not emails are delivered even to Spam or Bulk folder. In other words, the emails are not delivered at all, and thus cannot be found on Inbox nor Spam folders. If the emails were delivered, but been found on Spam or Bulk folder, then the domain or mail server is not been blacklisted by Hotmail or MSN.

Hence, the error code returned on the bounced emails should be used to confirm that the host is indeed on the Windows Live blacklist. Note that if the error code is of 400-series (421) which indicates too high volume or too large amount of emails been sent rather than spam, then the IP address or domain is not blacklist too.

Here’s tips on how to remove the IP address from MSN or Windows Live Hotmail blacklist to unban, unblock and whitelist the mail server IP address or domain again for that mails can be delivered properly and promptly.

The main task prior to applying for lifting of blacklist by MSN/Windows Live Hotmail is to ensure that the cause for the blacklist no longer happens. The main cause of blacklist is spam. In such cases, if your server has been compromised or been used without authorization to relay bulk volume of spam, action is required to rectify the issue. But a host can also be rejected or banned by mistake.

In any case, if you have concluded that spam sending issue has been fixed so the mail server should no longer be blacklisted, or that all emails originating from the host is legitimate or opt-in with opt-out feature available.

To begin the process to remove a mail server’s IP address from MSN/Hotmail’s blacklist, visit the following URL to complete and submit Sender Information for Hotmail Delivery form.


Many information is required, such as IP addresses of outbound mail server (as seen by the receiving mail server), whether the server is dedicated or shared, problem description, error messages contained in the bounce messages or SMTP logs, ISP used, operating system used, MTA (mail transport agent) used, mailing list management software used, how are bounce messages (non-delivery reports) handled by the system, frequency of the mailings, volume of the mailings, examples of email accounts on Microsoft’s systems that are the recipients, ability to telnet to port 25 of mx1.hotmail.com from mail servers, results of traceroute to from mail servers, example of email messages with full headers, URL of websites, how are recipients added (subscribed) to the mailing lists, option to unsubscribe (opt out), publishing of Sender Policy Framework (SPF) or Sender ID records for the IP and etc.

While not all information is required, it’s best to give as detailed information as possible in order to help Microsoft to decide if your IP address should be unblocked and removed from the blacklist.

It’s recommended to setup and configure proper SPF and PTR records in DNS for the mail server’s IP address prior to request for the removal from blacklist.

Within 2 or 3 business days, if Microsoft investigates and decides that the host is indeed do not send any unsolicited spam, you will receive an email from Windows Live Hotmail Sender Support Team which indicates that MSN/Windows Live has implemented a fix for the deliverability problem. Note that the removal from blacklist or unban/unblock process may take 24 – 48 hours to replicate completely throughout the Microsoft/Windows Live/MSN system.

To avoid been blacklisted again by Windows Live Hotmail system in future, Microsoft recommends system administrator to enroll in Junk Email Reporting Program (JMRP), a sender complaint feedback loop program which helps administrator to remove those Windows Live Hotmail customers who do not want to receive emails. Another program is Smart Network Data Services (SNDS) which allows a sender to monitor the ‘health’ of their IPs. Last but not least, especially for marketers and mass mailers, join and get qualified for SenderScore Certified Mail Program administered by Return Path, the only white listing service to which used by Microsoft, MSN and Windows Live services, which can help to improve mail deliverability and decrease email from being filtered to the Junk Email Folder.

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  • dario

    I have the same problem in Italy.

    A Virus came some months ago, we solved the problem, no more spam for our customers in 2 months, but we are still on MS blacklist… I have no word.
    I inscribed at the program JMRP, but it’s written that this inscription do not have anything in common with the reputation…. I have no words.
    The Sender Support Team is a PC that automatically reply…I have no words.
    I have to suggest to all my customes to change their account…
    MS is so un-professional….

    2 months of work between the italian telecom firm and MS and there is no solution…even if I asked an explanation to the line on MS social network … don’t let me talk!

  • Stuffed

    I have the same problem, after moving from a server in which I had a good email reputation of over 10 years, (I had to move to another server due to network issues and cost factors), and hence ended up with a new IP address. Hotmail is so stuck in their own hard-headedness that they won’t even consider the previous long standing IP reputation. It does not seem to matter if you are enrolled in the JMRP or if you are in the Smart Network Data Services, have a SPF, are a member of return path, have a good sender score, have a complaint rate of 0.1% with no spam trap hits, and are not in any blacklists. All things they repeatedly recommend like robots without brains. They continue to block and say that “your IP is does not qualify for mitigation”, are simply being unreasonable, and Hotmail is blocking emails to their own users without any legitimacy whatsover. So now on 1 end of the spectrum is the NSA prying into your privacy, on the other side is hotmail blocking your emails and not telling you users about it, it’s not about preventing any spam. I don’t know that it has to do with any rules, (because the more you comply with what they suggest the more frustrating it gets), or if there is just some manipulative control freak at the helm making decisions to block emails because he/she can. I would imagine though that there are many others and that the word will travel thru the internet if people tell what they are experiencing with hotmails illegitimate email blocking.

  • Steven


    I have follow your suggestion steps. But, Hotmail keep reject my IP mitigation process.
    They keep saying my IP is block by their smartscreen filter. And ask me review again and again.

    What to do?
    Try luck?

    Any Idea?

    • My Digital Life Edit

      Have you made sure your mail server does not actually send out spam?

      • Steven

        Yes. I can confirm I never send out spam mail. Hotmail said my IP did not have any offhand in their system. But they still do not want to do the IP mitigation for me.

        • My Digital Life Edit

          Then, just follow the instruction given by them.

          • Enverex

            There are NO further instructions given by them though, that’s the problem. If they refuse your request for removal (which they have with me after giving no reason why it was listed initially) their only follow up is “make sure you abide by the Hotmail policies” which still doesn’t help and doesn’t in any way aid in getting removed from the blacklist.

  • just_me

    Don't take me wrong but I'm running into the "550 SC-001" problem on a brand new server. And I don't see much reason giving Microsoft example mail addresses I'm trying to send to because these are private.

    Not to forget, if anyone would start with such systems Email would be basically dead.

    So instead of bitching with Microsoft and signing in at various Microsoft campaigns for sending Mail to registerd and verified users I just recommend serious users to not use the Hotmail / Live services at all.

    I've valid SPF / DKIM / PTR records so what does MS expect ?

    Sorry – if Hotmail / Live users don't want to recieve mail, their fault. They better use another service then that can guarantee wanted Mails make it to them.