Introduction
Syvel is a French API for detecting disposable and temporary email addresses, designed to protect your sign-up forms and maintain the quality of your user base.
What is a disposable email?
A disposable email (or throwaway email) is an address created for a single use — to sign up for a service without revealing your real address, bypass a free trial, or automate bulk registrations.
These addresses cause several problems:
- Degraded deliverability: bounces increase, your sender reputation drops
- Skewed analytics: your conversions and CRM segments no longer reflect reality
- Free-tier abuse: trial periods are bypassed in seconds
How does Syvel work?
Unlike solutions based on simple static lists, Syvel combines multiple signals:
Proprietary blacklist
A database of known disposable domains, updated every hour from the main open-source sources.
Real-time DNS analysis
Each domain is analyzed through its MX, SPF and DMARC records. A domain without SPF or DMARC, with a suspicious MX, receives a high score.
MX Fingerprinting (exclusive technology)
Our algorithm identifies new disposable domains before they even appear on a blacklist, by analyzing their DNS infrastructure. If a new domain points to the same MX server as hundreds of known disposable domains, it is immediately flagged.
Domain age
A domain created less than 24 hours ago with a complete email infrastructure is statistically suspicious.
Risk score 0–100
Each analysis returns a score from 0 to 100:
| Score | Meaning | Recommended action |
|---|---|---|
| 0–29 | Safe domain | Accept |
| 30–49 | Low risk | Accept with caution |
| 50–79 | High risk | Show a warning |
| 80–99 | Very likely disposable | Block |
| 100 | Confirmed blacklist | Block |
GDPR compliance
Syvel is designed privacy-first:
- Zero email storage: only the domain is analyzed, never the full address
- Hosted in France: Scaleway / OVH, sovereign data
- Logs max 90 days: automatic deletion
- Hash mode available: send only the SHA-256 of the email (Pro plan and above)
Ready to get started?
Head to the Quick Start Guide to make your first API call in under 5 minutes.