> Source: [sk184031](https://support.checkpoint.com/results/sk/sk184031)

# sk184031 - IOC Feed "Prevent" Action Fails to Block Emails on Quantum Security Gateways Running Gaia R81.20

| Property | Value |
|----------|-------|
| Solution ID | sk184031 |
| Date Created | 2025-09-21 |
| Last Modified | 2026-07-23 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R81.20 |

## Symptoms

- * Indicator of Compromise (IOC) feeds with Action: Prevent do not block emails as expected on Quantum Security Gateways.
* The issue occurs across multiple Quantum Security Gateways, not limited to a single device.
* The problem is consistently reproducible: emails from addresses listed in the IOC feed are not blocked.
* IOC feeds work as expected on Quantum Security Gateways running Gaia R81.10, but fail to block on Gaia R81.20.
* IOC entries are present and visible on the Quantum Security Gateways, and the correct Threat Prevention profiles are applied.
* No blocks are observed in logs for Gaia R81.20, while Gaia R81.10 shows successful blocks for the same IOC entries.

## Solution

This problem was fixed. The fix is included in:

* [Jumbo Hotfix Accumulator for R81.20](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.20/Default.htm) starting from Take 158

If you choose not to upgrade, Check Point can supply a **Hotfix** . [Contact Check Point Support](https://www.checkpoint.com/support-services/contact-support/) to get a Hotfix for this issue.  
A Support Engineer will make sure the Hotfix is compatible with your environment before providing the Hotfix.  
For faster resolution and verification, please collect [CPinfo files](http://supportcontent.checkpoint.com/solutions?id=sk92739) from the Security Management Server and Security Gateways involved in the case.

**Hotfix installation instructions:**   
Refer to [sk168597 - How to install a Hotfix](https://support.checkpoint.com/results/sk/sk168597).

- After applying the hotfix, confirm that emails from addresses listed in the IOC feed are blocked as expected.  
- Check Threat Prevention logs to ensure blocks are recorded for IOC entries with Action: Prevent.

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