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I have been having problems sending emails from my server to hotmail.com and live.com email addresses. I have read other posts on serverfault but they have not been helpful. Here is the error message. It is very vague

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 problems. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help. Email/network admins, please visit http://postmaster.live.com for email delivery information and support

I have visited http://postmaster.live.com and http://microsoft.com/senderid but nothing has worked. I have a mx record and a valid spf record: v=spf1 a mx ~all which passes google's validation. I have triple checked all spam lists and my IP is not on any list. I am at a loss, any suggestions?

marked as duplicate by Jenny D, masegaloeh, Hyppy, Katherine Villyard, Ward Apr 22 '15 at 3:01

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.


You don't have to be on a spam list. First try sending a single test email. Make sure it has a subject line and text body content. If that does not go through then you have been blocked due to ip/domain issues. Check the Smart Data Network Services to see the health of your ip space from hotmails perspective.

If it does go through, then it's content related. Check the policies and guidelines page for more details on what you can ana can't send to hotmail users.

  • I added my IP to SDNS but still no luck. It isn't content related either. Could it just take a while for the SDNS registration to propagate across the MS mail servers? – user16517 Aug 13 '10 at 19:28
  • what did the smart data network services say about your ip? – Jim B Aug 13 '10 at 21:36
  • It just says the ip has a "normal status" – user16517 Aug 16 '10 at 14:00

Enter your IP address in the "Multi-RBL Check" box here: http://www.anti-abuse.org

If you get any hits, that may well be your problem.

  • It is not listed in any of the RBL's checked by the Multi-RBL checker. I have tried other multi RBL listing searches as well and no results are ever found. – user16517 Aug 13 '10 at 20:41
  • Does it reject all messages or just particular ones you are trying to send? Register yourself accounts with Live/Hotmail and try sending yourself messages manually via telnet with SMTP commands for the IP addresses you are working with. If the simple test messages make it through, but "real" messages do not, then the mail content itself (anything from headers to HTML tags) could be increasing the spamminess of your mail past a certain threshold. – Geoff Fritz Aug 13 '10 at 20:58
  • No messages make it through, even simple plain text ones with standard headers. – user16517 Aug 16 '10 at 13:58

Chances are you're reporting broadband provider address space (dsl, cable, etc) somewhere in your received headers.

We started seeing policy refusals after many clients switched to big name broadband providers with the economic downturn. Our fix was to proxy these client's emails through a host that stripped all "received by" headers, making it appear that our mail all originated locally.

It's a pain - we used to simply record everything in the usual way by adding received headers. Thanks to these inane policy filters, we started encoding originating IP addresses and putting them backwards into custom headers these firms weren't looking at, and like magic, the problem went away. They no longer knew the mails originated from DSL.

There are a few big name folks in on this. I won't name them. Worst of all, it looks like a shakedown scheme to us. They wanted X dollars annually per company to approve a company to use a broadband address, and only months later made it possible to "register your company" for free.

  • I checked the received headers and my isp's address space is not reported – user16517 Aug 16 '10 at 16:04
  • ianion, look up the ip address your server is using and check the reverse DNS for that IP address. Change any numbers to X and then post the reverse lookup here. – voltaire Aug 16 '10 at 21:21
  • xxx.xxx.xxx.xxx.in-addr.arpa domain name pointer <mydomain>.com. mydomain is of course my domain. rDNS is correct. – user16517 Aug 16 '10 at 23:08
  • in-addr.arpa : Ask your isp to change your reverse (assuming a fixed ip) to mail.mydomain.com. However, I am beginning to believe that it's most likely message content/format/volume related. And if your ISP is spammer friendly, you might have bigger problems. PLAN B: find (or pay) someone to give you an SMTP relay for your server. – voltaire Aug 17 '10 at 16:52

Ok, I have finally unblocked my mail server from hotmail/live/msn networks! Originally, I had the dns mx record and spf record set correctly, had the correct rdns value, and was not on any block lists.

I then signed up with the Smart Data Network Services, then submitted my info via Microsoft's Sender ID SPF Record Submission Form, then enrolled in the Junk Mail Reporting program, then had a back and forth email conversation with a few support people, sending them information and filling out questionnaires, finally convincing them to remove my mail server from their block lists.

Phew, should it really be that difficult? Other mail services like gmail handle spam blocking just fine without making it such an epic battle to unblock your mail server.


How many external IP Addresses does your company have? NAT your email server outbound via a different IP and see what happens.

Just cause you aren't on the RBL doesn't mean you aren't on Hotmail's bad list. :)

As a rule, you should make sure all user traffic goes out a different IP so if clients are compromised your email doesn't suffer.

  • This is not for a company, this is my personal server and email addresses. I only have one server/ip. – user16517 Aug 16 '10 at 14:14

Phew, should it really be that difficult? Other mail services like gmail handle spam blocking just fine without making it such an epic battle to unblock your mail server.

The IP address may have been previously tainted. We've had to deal with such an issue a couple of times and yes it can be that difficult. The other option is like voltaire suggested to use a delivery service which Yahoo and AOL did/attempted to promote back in the day with I think it was Goodmail. Other options are Critsend and StrongMail; none of which I have experience with.

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