Detect Messages with Spam or Malware Using Zero-Hour Auto Purge (ZAP) in Exchange Online Protection — A Technical Deep Dive
1. Overview and Context Zero-Hour Auto Purge (ZAP) is a post-delivery remediation mechanism built into Exchange Online Protection (EOP), enabling retroactive mitigation of malware, phishing, and spam threats after messages have entered cloud mailboxes. This functionality arises in response to two critical realities: Evolving threat intelligence: New spam/malware signatures and heuristics are continuously updated,…