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[220.127.116.11] 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[18.104.22.168] 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 22.214.171.124 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.