You’re attempting to upload the IOC blocklist via API, but the maximum allowed is 10,000 blocklist entries.
Email Security.Cloud
The attempted IOC blocklist upload surpasses the system’s maximum allowed limit. A hard cap of 10,000 entries is currently enforced.
Make sure the number of entries does not exceed the maximum limit outlined above. We recommend reviewing the current list to identify and remove any duplicates or outdated entries to accommodate new ones.