Resolved after 22 hours 39 minutes, on March 17, 2026.
The issue has been resolved, and sending to Microsoft-owned domains has been restored.
Update timeline
- investigating Mar 17, 2026, 03:47 PM UTC
We are currently investigating an issue affecting deliverability to Microsoft inbox providers. At this time, some emails sent to Outlook.com, Hotmail.com, and other Microsoft-owned domains may experience delivery delays.
- identified Mar 17, 2026, 03:58 PM UTC
We've identified that Microsoft addresses (outlook.com, hotmail.com, and other Microsoft-owned domains) are experiencing delivery delays at an elevated rate. We've informed Microsoft and are monitoring.
- identified Mar 18, 2026, 12:32 AM UTC
We’ve identified that this issue is impacting domains in the eu-west-1 region. We’re actively escalating with Microsoft to resolve this as quickly as possible. Please reach out to [email protected] for any questions and concerns.
- monitoring Mar 18, 2026, 08:53 AM UTC
We’re seeing delivery to Outlook.com, Hotmail.com, and other Microsoft-owned domains return to normal. Emails are now being delivered in a timely manner. We’ll continue to monitor closely.
- resolved Mar 18, 2026, 02:27 PM UTC
The issue has been resolved, and sending to Microsoft-owned domains has been restored.
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