After cleaning out out email on our own mail server by testing and removing invalid emails, we couldn't send emails to anything Microsoft anymore, hotmail, outlook, msn, live. We would get an error report stating that:

Looking up the error code tells me that we have been namespace mining, which is true in a way I suppose, but now we're in a situation where we can't send emails to 12,000 customers who want to recieve our emails. After filling out a form where we send our IP in to be checked, we got another email stating:

"We have completed reviewing the IP(s) you submitted. The following table contains the results of our investigation. 

 

More information needed

*Insert our IP address*

There are indications that the above IP(s) are engaged in namespace mining. Outlook.com is blocking all email sent from this IP.

Namespace mining is a method commonly used by malicious senders to generate lists of email addresses. This approach uses automation to sift through possible email names seeking to identify valid email addresses, e.g., *** Email address is removed for privacy ***, *** Email address is removed for privacy ***, and *** Email address is removed for privacy ***.

You must correct the problem and you must stop the behavior described above. We recommend that you work with your email or network administrator to review the logs of your email servers. Check the sending log files and concentrate on logs that are sending to nonexistent @hotmail.com, @live.com, @msn.com, @outlook.com?with multiple tries and failures."

And ending with:

"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 better ensure deliverability to Outlook.com users. 

 

Thank you, 

 

Outlook.com Deliverability Support"

Now, this is all very well and good, but there is no solution to our problem here, no-one to contact or anything.

After this we tried phoning up Microsoft support, only to get bounced around in circles throughout the system as no-one there seemed to know what was going on.

Any help that provides results would be greatly appreciated.

Thanks,

William Bee