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Microsoft tests fix for Exchange Online and Outlook outage lasting over 17 hours
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Microsoft confirmed a widespread outage affecting Exchange Online and Outlook that began around 11:30AM ET on Monday, causing email delays and failures for over 17 hours, and says it is now testing a fix.
A 17-hour-plus outage on core email infrastructure means delayed or failed mail delivery for organisations relying on Exchange Online, with potential downstream impact on business operations and SLA obligations. The fact that Microsoft is still only testing a fix this far in suggests the root cause is non-trivial. Engineers responsible for mail routing or dependent workflows should verify delivery once service is restored, as queued messages may not all flush cleanly.
Written by elseif from the cluster below · every claim links back to a sourceThe three things worth knowing
Microsoft confirmed a widespread outage affecting Exchange Online and Outlook starting around 11:30AM ET on Monday.
The outage caused email delays and failures and lasted over 17 hours.
Microsoft says it is testing a fix but has not confirmed full restoration.
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