Since more than 1 month ago we are having our email from one of our servers systematically tagged as junk by Hotmail Smartscreen filter.

We have taken the following actions/measures without success:

  • Reverse DNS matching the sender IP.
  • SPF, DomainKeys and DKIM activated and pass (confirmed by che[email protected] and by Hotmail email header itself).
  • DNSBL cleaned in mxtoolbox.com, spamhaus, barracuda and Trend Micro.
  • We impose hourly and daily email sending limits (90 emails/destinataries per hour and mailbox).
  • Our datacenter also blocks the 25 destination port when it detects special spam or virus sending.
  • We have tried different different IP's, even acquired new failover ones with previous DNSBL check and reverse DNS.
  • We have tried different email addresses, even created new ones and different domains.
  • The IP's that we have used are enrolled in MS JMRP and we received very few user FBL complains (one-two per month).
  • Contact through Hotmail Sender Information Form and subsequent email interaction with their operators have not yielded any advancement. They always reply that "we do not see any issues with your IP as of today".
  • SMTP server (postfix) logs show normal email acceptance (immediate 250 response) by Hotmail servers.

We are a sharing hosting company that provide web and email services to multiple customers in a server and IP address. It is true that we have some spam and virus infection from our clients (maxium 1 per week out of hundreds of legitimate senders) but in any case our limits and our datacenter limits hold.

We would like to know if there is a specific positive reporting link such as this one in Gmail to inform Hotmail directly from our side that our email sending is legitimate.

Otherwise we rely on our client's destinataries to positively counter-mark Hotmail spam status (if they are knowleageble and care to do so).

  • 1
    Where do you get the IPs from ? If it's a dedicated server company, they sometimes have bad reputation and I won't be surprised if Hotmail keeps a record of the reputation of the whole netblock, thus even if you remove yourself from all spam RBLs, you're still in trouble just because Hotmail thinks your netblock is bad.
    – user186340
    Apr 22, 2015 at 12:36
  • Have you tried this solution ?
    – user186340
    May 3, 2015 at 7:26

4 Answers 4


Only thing left. The email content. If a image only crosslinked in exemple to somewhere, it will trigger a bad spam quote.

  • 2
    This should really be a comment. And I think you don't understand how Hotmail works, it's not a question of message contents - sometimes they just don't like you for whatever reason and you can't do anything to change it, you need to battle your way through the <expletive> from their customer service (who don't care about what you say and copy/paste a stupid automated reply) which is impossible unless you're a large company or know someone inside Microsoft.
    – user186340
    Apr 22, 2015 at 12:29
  • @AndréDaniel You don't know how it work either. MS is a quoted public company. It does not hate someone because of an obscure reason. Does the IP is blacklisted ? NO. Does the customer received a email non-delivery because of the SPF record. NO. It's told, the remote SMTP accepted the email correctly. The email was received. PERIOD. If you think Hotmail block for obscure reason, then fill an antitrust complaint (justice.gov/atr/contact/newcase.html?hc_location=ufi) . PERIOD. Can it be because of email content, YES.
    – yagmoth555
    Apr 22, 2015 at 12:49
  • 1
    And of course, I will add, they will not share how they score email for security issue.
    – yagmoth555
    Apr 22, 2015 at 13:05
  • 2
    @AndréDaniel One of my customer had this kind of issue, and it was a simple email signature. The image was linked to another website (not the same as the domain name). Removed that, and after all went well with Hotmail.
    – yagmoth555
    Apr 22, 2015 at 13:14
  • 3
    By "they don't like you" I obviously didn't mean personal hate, but that their algorithm has for some obscure reason decided your IP or netblock is bad (maybe based on really old spam sent by the previous owner of the IPs). I've had this problem and the content wasn't the culprit - even test messages with just "Hello" in plain text (with SPF and DKIM) were flagged as spam. Once I finally succeeded in contacting someone at Microsoft, this same "Hello" message (and all subsequent mails) arrived just fine in the inbox.
    – user186340
    Apr 23, 2015 at 14:57

What I find interesting is that only 1 of your Mail IP Address is having the issues, I'm assuming the other ones are working fine. If the IP you're having issues with was recently assigned. You might need to balance the load to force the majority of the sending from a different IP until it warms up as indicated in Hotmail's troubleshooting guide.


Also, send an email to "[email protected]", it works like port25, but it does more extensive testing on all the MX servers you have - maybe something else isn't configured correctly.


You could publish a GPO to all clients which configures the junk email settings.

"Specify path to Safe Senders list Properties" and Deploy such a SafeSenderList.txt to all Clients which have all your "Safe Senders" in it.

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