Delays in sending emails to Microsoft domains

Update timeline

1. investigating Jan 15, 2026, 10:24 AM UTC

   We are currently investing reported delays when sending emails towards Microsoft email domains

2. investigating Jan 15, 2026, 11:06 AM UTC

   Impact is currently scoped to EU region only. Investigation ongoing; tickets raised to Microsoft to further investigation.

3. investigating Jan 15, 2026, 11:13 AM UTC

   We continue to work with Microsoft on full mitigation. They are currently experiencing infrastructure issues that is causing them to incorrectly block legitimate traffic from multiple Bird IP ranges. Our sending infrastructure and email traffic are operating normally. All other mailbox providers are receiving mail without issue. Microsoft is aware of the issue and is actively investigating. We are in contact with their team and monitoring for resolution. We expect this to be resolved once Microsoft completes their fix. Messages will retry automatically - no action needed from you

4. investigating Jan 15, 2026, 11:50 AM UTC

   Microsoft continues to investigate the issue. We are actively in contact with their team.

5. identified Jan 15, 2026, 01:25 PM UTC

   We continue to work with Microsoft on these delays. We are in active contact with their delivery team and working towards full resolution.

6. identified Jan 15, 2026, 01:49 PM UTC

   We have started to receive reports from Microsoft that they are implementing mitigations within their environment. We continue to monitor and coordinate with them for full resolution.

7. identified Jan 16, 2026, 04:03 PM UTC

   We continue to see some delays at Microsoft domains and are working with Microsoft to remediate. At this time, Microsoft is aware and continues to investigate.

8. monitoring Jan 17, 2026, 11:30 PM UTC

   We have seen stabilization, but are still seeing Microsoft delays in rare cases. Our team is mitigating with Microsoft as those occur. We are going to keep the status page in Monitoring state through the weekend as we continue to monitor for a full recovery at Microsoft.

9. monitoring Jan 19, 2026, 06:18 PM UTC

   We continue to see improvement with Microsoft delivery, though isolated cases of delays persist. Microsoft's mitigations are largely effective, but we're still working with their team to address edge cases as they arise. We will continue to maintain heightened monitoring through the week to ensure complete stabilization. No action is required from senders - any affected messages will continue to retry automatically.

10. monitoring Jan 23, 2026, 05:11 AM UTC

    We continue to receive reports of outages at Microsoft, as well as delayed mail sending to Microsoft and their related properties. If you are experiencing delays or IP blocks in sending to Microsoft related properties, please open a ticket with your Technical Account Manager or email [email protected] (or your dedicated support channel if applicable). For detals around the Microsoft 365 please reference Microsoft's Status Page at: https://status.cloud.microsoft/m365

11. resolved Jan 27, 2026, 04:33 PM UTC

    We continue to receive sporadic reports of outages at Microsoft, as well as delayed mail sending to Microsoft and their related properties. But have seen recovery for most senders. If you are experiencing delays or IP blocks in sending to Microsoft related properties, please open a ticket with your Technical Account Manager or email [email protected] (or your dedicated support channel if applicable).