Earlier today we began to see reports of issues contacting outlook.com, hotmail.com and associated addresses for the free mail services offered by Microsoft. After investigations we could see this was only impacting a subset of mail flow to these domains. Further to this the failures were of such an intermittent nature it suggested an issue with the Microsoft provided services. We opened a support ticket with Microsoft Postmaster services which received an almost instant response confirming no issues with our servers / IP addresses, i.e. we were not blacklisted. At this time the Microsoft support personnel did not confirm they had encountered any issues.
However, Microsoft have subsequently posted a status message acknowledging that the delivery issues were caused by ‘degraded’ components within their infrastructure. As of 21:00 (GMT+1) the latest status information indicates they are still working to resolve the issues within the infrastructure serving outlook.com, hotmail.com/co.uk, live.com/co.uk.