You may have missed emails on Outlook for days, as Microsoft confirms its spam rule wrongly blocked them and blamed senders’ settings
AI-summarised brief · reviewed before publication
Microsoft confirmed that an update to Outlook’s spam rules mistakenly blocked legitimate emails, causing many users to miss messages from Outlook.com, Hotmail.com, Live.com, and MSN.com. The error, identified on November 5, led to authentication‑related bounce messages (e.g., “550 5.7.1 Message lacks SPF/DKIM/DMARC Auth Records”). Microsoft rolled back the update and restored mail flow by November 9, 12:02 CET, and clarified that senders need not alter SPF, DKIM, or DMARC settings. Users who missed emails must request resends, as lost messages cannot be recovered.
💡 Why It Matters
- · The incident exposed a critical flaw in Microsoft’s spam filtering that disrupted everyday communication for thousands of users, underscoring the importance of accurate email authentication checks in large‑scale email services.