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ChangesSparkPostMicrosoft outage: delays delivering to Outlook, Hotmail and Office 365

SparkPost: Incident updated: Microsoft outage: delays delivering to Outlook, Hotmail and Office 365

Incident updateNot classified yetChanged status.sparkpost.com (opens in new tab)
Summary

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What changed

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AddedUpdateidentified#1
Before: not present
After: Microsoft has identified a likely cause of incident EX1550543. A process on its servers that establishes secure connections is becoming overwhelmed, which stops the servers from handling requests. Microsoft has started rolling back a recent network configuration change that coincides with the start of the problem. It is also testing a fix that it plans to apply across all affected servers. Microsoft expects to post its next update by 02:00 UTC, and you can follow it at https://status.cloud.microsoft/m365/referrer=serviceStatusRedirect. Delivery to Outlook.com, Hotmail, Live, MSN and Office 365 recipients is still heavily delayed. More mail is getting through than earlier this evening, but most delivery attempts to Microsoft are still being deferred, and we have not yet seen the effect of Microsoft's changes. SparkPost's systems are working normally. Messages still waiting for Microsoft are queued and retried automatically, so please don't resend them, because that would create duplicates once they are delivered. Because the problem has now lasted more than seven hours, messages with an expiration time of up to several hours may expire before Microsoft accepts them. Each expired message generates a bounce event, and since expired messages are no longer queued, you can decide whether to resend those specific messages.

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History of this incident

TodayFriday, November 13Fri, Nov 13

3 incident changes

YesterdayThursday, November 12Thu, Nov 12

2 incident changes

Cite this

Incident updated: Microsoft outage: delays delivering to Outlook, Hotmail and Office 365 on SparkPost’s status page, changed 2026-11-13 01:13 UTC (change 4 of 5).

Title
Incident updated: Microsoft outage: delays delivering to Outlook, Hotmail and Office 365
Vendor
SparkPost
Date
URL
https://rewindex.com/change/reff26e71f2a8e5

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