550 5.7.705 Tenant Email Block 55+ Hours - Support Unresolved

This is a tenant level enforcement block, so the Restricted Entities page cannot remove it. Only Microsoft 365 Support can validate the remediation and request backend delisting. Consolidate updates into one ticket, provide a recent NDR and message trace, document that compromised accounts, connectors, forwarding, and bulk sending were remediated, then request a severity review and escalation to the Exchange Online Protection or Microsoft Defender for Office 365 escalation team. Use the Microsoft 365 admin support phone channel if the assigned engineer is unresponsive, and involve the reseller if the subscription is partner managed. The public forum cannot lift this block, and there is no administrator self service bypass for 550 5.7.705.. Learn more here: https://mstack360.com/enterprise-microsoft-365-security-implementation/