# Sec1 ZeroDefender vs Spamhaus Policy Blocklist (PBL): side-by-side comparison (2026)

[Sec1 ZeroDefender](https://cybersectools.com/tools/sec1-zerodefender) is a commercial [threat intel feeds](https://cybersectools.com/categories/threat-intel-feeds) solution by [Sec1](https://cybersectools.com/companies/sec1). [Spamhaus Policy Blocklist (PBL)](https://cybersectools.com/tools/spamhaus-policy-blocklist-pbl) is a free [threat intel feeds](https://cybersectools.com/categories/threat-intel-feeds) solution by [Spamhaus](https://cybersectools.com/companies/spamhaus). Features, integrations, deployment and the company behind each one, side by side.

## Side-by-side comparison

| | Sec1 ZeroDefender | Spamhaus Policy Blocklist (PBL) |
|---|---|---|
| Pricing model | Commercial | Free |
| Category | Threat Intel Feeds | Threat Intel Feeds |
| Verified | No | No |
| Deployment type | Cloud | Cloud |
| Company size fit | Startup, SMB, Mid-Market, Enterprise | Startup, SMB, Mid-Market, Enterprise |
| Company | Sec1 | Spamhaus |
| Headquarters | – | – |

### Use cases and capabilities

| | Sec1 ZeroDefender | Spamhaus Policy Blocklist (PBL) |
|---|---|---|
| Alerting | Yes | – |
| Zero Day | Yes | – |
| Cyber Threat Intelligence | Yes | – |
| Spam Prevention | – | Yes |
| Botnet | – | Yes |
| IP Lookup | – | Yes |
| Network Protection | – | Yes |
| SMTP | – | Yes |

### Core features

**Sec1 ZeroDefender**

8 features listed. Sign in on the page to see them.

**Spamhaus Policy Blocklist (PBL)**

8 features listed. Sign in on the page to see them.

### Integrations

**Sec1 ZeroDefender**

7 integrations listed. Sign in on the page to see them.

**Spamhaus Policy Blocklist (PBL)**

2 integrations listed. Sign in on the page to see them.

## Which one fits you

Based on what each listing shows: deployment, company size, price and open source.

- [Spamhaus Policy Blocklist (PBL)](https://cybersectools.com/tools/spamhaus-policy-blocklist-pbl) fits if you need a free product.

## Sec1 ZeroDefender vs Spamhaus Policy Blocklist (PBL) FAQ

Common questions when comparing Sec1 ZeroDefender vs Spamhaus Policy Blocklist (PBL) for threat intel feeds.

### What is the difference between Sec1 ZeroDefender and Spamhaus Policy Blocklist (PBL)?

**Sec1 ZeroDefender**: Real-time zero-day vulnerability detection and alerting platform. Built by Sec1.

**Spamhaus Policy Blocklist (PBL)**: DNSBL of end-user IP ranges that should not send email directly to MX servers. Built by Spamhaus.

The table above shows where their features, integrations, deployment and company size fit differ.

### Who makes Sec1 ZeroDefender and Spamhaus Policy Blocklist (PBL)?

**Sec1 ZeroDefender** is made by Sec1. **Spamhaus Policy Blocklist (PBL)** is made by Spamhaus. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit.

### Is Sec1 ZeroDefender a good alternative to Spamhaus Policy Blocklist (PBL)?

Often, yes. Sec1 ZeroDefender and Spamhaus Policy Blocklist (PBL) are both Threat Intel Feeds products. Key differences: Sec1 ZeroDefender is Commercial while Spamhaus Policy Blocklist (PBL) is Free. Use the table above to see where features, deployment and company size fit differ.

## Related comparisons

- [Sec1 ZeroDefender vs IPQS IP Address Block List](https://cybersectools.com/compare/ipqs-ip-address-block-list-vs-sec1-zerodefender)
- [Sec1 ZeroDefender vs ZeroFox Threat Intelligence Feeds](https://cybersectools.com/compare/sec1-zerodefender-vs-zerofox-threat-intelligence-feeds)
- [Sec1 ZeroDefender vs Nozomi Networks Threat Intelligence](https://cybersectools.com/compare/nozomi-networks-threat-intelligence-vs-sec1-zerodefender)
- [Spamhaus Policy Blocklist (PBL) vs IPQS IP Address Block List](https://cybersectools.com/compare/ipqs-ip-address-block-list-vs-spamhaus-policy-blocklist-pbl)
- [Spamhaus Policy Blocklist (PBL) vs ZeroFox Threat Intelligence Feeds](https://cybersectools.com/compare/spamhaus-policy-blocklist-pbl-vs-zerofox-threat-intelligence-feeds)
- [Spamhaus Policy Blocklist (PBL) vs Nozomi Networks Threat Intelligence](https://cybersectools.com/compare/nozomi-networks-threat-intelligence-vs-spamhaus-policy-blocklist-pbl)

## Alternatives to each

- [See all Sec1 ZeroDefender alternatives](https://cybersectools.com/alternatives/sec1-zerodefender)
- [See all Spamhaus Policy Blocklist (PBL) alternatives](https://cybersectools.com/alternatives/spamhaus-policy-blocklist-pbl)

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Source: https://cybersectools.com/compare/sec1-zerodefender-vs-spamhaus-policy-blocklist-pbl

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More on Sec1 ZeroDefender and Spamhaus Policy Blocklist (PBL): funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=compare-md