From The Conversation · Doug Jacobson · · 1m
Microsoft 365 outage: Why email fails differently
Microsoft 365 email outage takes days to fix due to old email architecture.
In brief
Microsoft 365 email outage takes days to fix due to old email architecture. Microsoft 365 email service outages take hours to days to resolve because email uses a decentralized system that queues messages until the provider recovers. Originally reported by The Conversation.
Microsoft 365 outage starts
Microsoft 365 services stopped working on Nov. 12, 2026.
Email outage differs from other outages
The outage affected Microsoft 365 email, Teams, and Copilot, unlike typical internet outages.
Microsoft reports ongoing issues
Microsoft said on Nov. 13 that some users may still experience email delays.
Email's old architecture
Email uses a decentralized 'store-and-forward' system that doesn't stop sending messages when down.
Email traffic jams during outages
Millions of messages pile up in queues as email servers try to resend emails to the downed provider.
Recovery takes hours to days
Fixing the outage causes a backlog of messages that take hours to days to process.
At a glance
Microsoft 365 email service outages take hours to days to resolve because email uses a decentralized system that queues messages until the provider recovers.
