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Microsoft Anti-Spam Engine False Positives Affect Exchange Online and Teams

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📰 1 unique sources, 1 articles

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Microsoft's anti-spam engine has incorrectly flagged URLs and emails as malicious, causing disruptions in Exchange Online and Microsoft Teams. The issue began on September 5, 2025, affecting URL links and email delivery. Microsoft has identified over 6,000 impacted URLs and is working to resolve the problem. The bug has led to false positive alerts and email quarantines, impacting users globally. The issue stems from the anti-spam engine incorrectly tagging URLs within other URLs as potentially malicious. Microsoft has deployed a partial fix but continues to address residual impacts. The root cause analysis is ongoing.

Timeline

  1. 09.09.2025 16:40 📰 1 articles · ⏱ 7d ago

    Microsoft Anti-Spam Engine False Positives Affect Exchange Online and Teams

    On September 5, 2025, Microsoft's anti-spam engine began incorrectly flagging URLs and emails as malicious, causing disruptions in Exchange Online and Microsoft Teams. The issue has affected over 6,000 URLs, leading to false positive alerts and email quarantines. Microsoft has deployed a partial fix but continues to address residual impacts. The root cause analysis is ongoing.

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