Exchange Online: Update to bulk email filtering for enhanced accuracy

Exchange Online is all set to introduce an update to its bulk email filtering system. This update will enhance the assignment of Bulk Complaint Level (BCL) scores when dealing with connectors and Composite Authentication (CAUTH) is set to none. Using this new system, intermediaries in email traffic are factored into the scoring system, providing more accurate reflections of bulk email traffic and hence, more consistent bulk email filtering. This update is expected to roll out worldwide, GCC, and GCC High by late October 2024. Hence, admins using connectors should review logs to assess the impact of the updated BCL scoring and evaluate any custom rules or configurations in place to ensure optimal filtering based on the new scoring system.

The post Exchange Online: Update to bulk email filtering for enhanced accuracy on M365 Admin has more details on how the update will affect organizations and what admins need to do to prepare for this update.