Email delivery delays affecting Microsoft 365 recipients and senders

Update timeline

1. investigating Sep 04, 2026, 09:34 AM UTC

   We are investigating delays in email delivery to and from Microsoft 365 tenants. Users may experience slower than normal sending and receiving of messages involving Microsoft 365 addresses. No email has been lost. Affected messages are queued on our mail servers and will be delivered automatically once delivery times return to normal. Current indications point to an issue within Microsoft 365’s infrastructure, outside our platform. We are monitoring Microsoft’s service health reports and will update this page as more information becomes available.

2. investigating Sep 04, 2026, 10:33 AM UTC

   We are monitoring delays in email delivery to and from Microsoft 365 tenants. Users may experience slower than normal sending and receiving of messages involving Microsoft 365 addresses. Microsoft 365 is also investigating the issue at themselves, their internal issue ID is EX1467029 No email has been lost. Affected messages are queued on our mail servers and will be delivered automatically once delivery times return to normal. Current indications point to an issue within Microsoft 365’s infrastructure, outside our platform. We are monitoring Microsoft’s service health reports and will update this page as more information becomes available.

3. investigating Sep 04, 2026, 11:07 AM UTC

   We have found if customers who are affected by this issue follow our guide for creating a inbound connector, the problem may be solved within 10-30 minutes of creation. Please follow the guide found here https://helpdesk.vipre.com/hc/en-us/articles/360007336418-Office-365-Receive-connector. In the meantime we will continue to monitor the delays in email delivery to and from Microsoft 365 tenants. We are monitoring Microsoft’s service health reports and will update this page as more information becomes available.

4. investigating Sep 04, 2026, 11:44 AM UTC

   We have found that affected customers can resolve the issue by creating an inbound connector in Microsoft 365. Where this has been applied, delivery typically returns to normal within 10–30 minutes. If you have previously configured a connector, please check it first — we are seeing cases where existing Microsoft 365 connectors have since been disabled. Re-enabling the connector may resolve the issue without further changes. If you do not have a connector configured, follow our setup guide: https://helpdesk.vipre.com/hc/en-us/articles/360007336418-Office-365-Receive-connector In the meantime, we continue to monitor delivery delays to and from Microsoft 365 tenants alongside Microsoft’s service health reports, and will update this page as more information becomes available.

5. monitoring Sep 04, 2026, 01:42 PM UTC

   We are seeing emails being delivered to microsoft, and we are still monitoring the progress of the incident. We still urge affected customers to create an inbound connector in Microsoft 365 as this can prevent this issue from happening in the future. If you do not have a connector configured, follow our setup guide: https://helpdesk.vipre.com/hc/en-us/articles/360007336418-Office-365-Receive-connector In the meantime, we continue to monitor delivery delays to and from Microsoft 365 tenants alongside Microsoft’s service health reports, and will update this page as more information becomes available.

6. monitoring Sep 04, 2026, 02:45 PM UTC

   We are seeing emails successfully delivering to Microsoft 365, and our team continues to closely monitor overall incident resolution. We strongly encourage affected customers to configure an inbound connector in Microsoft 365 to help prevent future delivery disruptions. You can follow our step-by-step setup guide here: Office 365 Receive Connector Guide. In the meantime, we are actively tracking delivery delays alongside Microsoft’s service health reports. We will provide further updates as new information becomes available.

7. monitoring Sep 04, 2026, 04:31 PM UTC

   We are seeing emails successfully delivering to Microsoft 365, though some delivery delays persist. Our team continues to closely monitor overall incident resolution. We strongly encourage affected customers to configure an inbound connector in Microsoft 365 to help prevent future delivery disruptions. You can follow our step-by-step setup guide here: Office 365 Receive Connector Guide. In the meantime, we are actively tracking delivery delays alongside Microsoft’s service health reports and will provide further updates as new information becomes available.

8. resolved Sep 04, 2026, 08:11 PM UTC

   Emails are now delivering normally to Microsoft 365, and delivery delays have fully cleared. Our team has verified that mail flow metrics and queue processing times have returned to baseline levels. To help prevent similar delivery disruptions in the future, we strongly recommend that affected customers configure an inbound connector in Microsoft 365. You can follow our step-by-step instructions in the Office 365 Receive Connector Guide.