Microsoft 365 outage: What happens to emails you send & receive while Outlook is down

With Microsoft 365 down for more than 16 hours, Microsoft has extended the email timeout window for Outlook to 48 hours to protect delayed mail. Emails sent and received during the outage are largely stuck in a queue rather than lost, and should arrive late once services recover. Here’s what happens to your Outlook emails, why they may land in bursts, and when to resend them.