Mimecast Defender Mailflow fails to apply junk actions to detections - May 2025

Known Issue

Date Logged	May 5th, 2025
Product(s)	Email Security Cloud Integrated (CI)
Status	Not Fixing

Issue

We are aware that the Defender does not apply the Move to Junk action for Detections made before messages are sent to Cloud Integrated for scanning, causing those messages to be held up. This happens because the action relies on transport rules, allowing Cloud Integrated rules to override it. This issue occurs only in Monitor mode, where detection actions aren't applied.

Customers using Protect mode should not have this issue.

This limitation is known and is not scheduled for resolution by the Product Team. Please contact your Account Team to discuss how this issue affects your organizational priorities.

Workaround

• N/A.