We provide hosted email for a number of customers on a shared server and it has been functioning fine for years.

Since last week, it appears the IP is being actively blocked by mail.protection.outlook.com.

We are already enrolled in SNDS and all services are reporting as normal.

Same with JMRP.

Blacklist checks show no problems and senderscore is fine.

We have reported the issue to Hotmail sender support last Friday and were told that the problem was being mitigated - no details provided.

On Monday it was still a problem and the sender support response was that the problem was not mitigated but again no detail provided.

After several follow ups all we got was a recommendation to enrol in SNDS and JMRP (which we already were in).

Not further response over the last 24 hrs despite requests.

This is a business critical issue that need to be solved - how can we find out what the issue is?

Hi,

>>IP is being actively blocked by mail.protection.outlook.com

Based on the description, we can refer to the following blog to see if it helps.

Ensuring email from an IP isn't blocked by Hotmail

https://kb.iweb.com/entries/22941042-Ensuring-email-from-an-IP-isn-t-blocked-by-Hotmail-

If the issue persists, in order to get better help, it's still recommended that we contact dedicated support team to ask for advice.

Outlook.com Community

http://answers.microsoft.com/en-us/outlook_com/forum

Best regards,

Frank Shen