ORCA.100: Bulk Complaint Level threshold is between 4 and 6.
| ID | ORCA.100 |
| Severity | Low |
| Suite | ORCA |
| Product | Defender |
| Related products | Exchange Online |
| Feature | Anti-spam |
| Security area | Email and collaboration protection |
| Resource type | Policy |
| User impact of fixing | Low |
| Effort to fix | Low |
| Framework controls | nist-800-53-r5:SI-8 Spam Protection |
| Reads from | Exchange Online |
What this checks and how to fix it
Section titled “What this checks and how to fix it”The differentiation between bulk and spam can sometimes be subjective. The bulk complaint level is based on the number of complaints from the sender. Decreasing the threshold can decrease the amount of perceived spam received, however, too low may be considered too strict.
Remediation action
Section titled “Remediation action”Set the Bulk Complaint Level threshold to be 6.
Related Links
Section titled “Related Links”- Bulk Complaint Level values
- Microsoft 365 Defender Portal - Anti-spam settings
- Recommended settings for EOP and Microsoft Defender for Office 365 security
Mito check, based on ORCA. Author: soulemike. Open-source licences.
Open-source licences. CIS Benchmark material © Center for Internet Security, Inc.; CISA SCuBA baselines are public domain (CC0).
© 2026 Virtual Petals. Mito is a Virtual Petals service, hosted in Microsoft Azure UAE North.