EmailScore
Unit Economics & Fraud Defense

Stop Multi-Accounting & Free Trial Abuse

Opportunistic users and automated scripts abuse promotional credits and LLM tokens by churning through Gmail dots, plus-addressing, and disposable domains. EmailScore normalizes identities and prevents multi-accounting in <0.3ms.

100%
Salt Stripping
Normalized dots & +tags
SHA-256
Identity Hash
Deterministic user clustering
<0.3ms
Check Speed
Zero signup delay
99.11%
Threat Recall
Bot & churn catch rate
Multi-Accounting Techniques

How Fraudsters Game Your Free Tier

Free trial abusers exploit standard database uniqueness constraints using trivial email tricks.

Identity Normalization

Subaddress & Salt Stripping

Gmail, Fastmail, and Proton ignore '+' tags ([email protected]). EmailScore strips subaddresses and computes canonical normalized roots before database insertion.

RFC Variance Handling

Gmail Dot-Stuffing Normalization

To Gmail, '[email protected]' and '[email protected]' route to the same inbox, creating up to 2^(n-1) unique signup strings. EmailScore collapses all dot variants to a single root.

Cross-Account Correlation

Deterministic Identity Hash

Our API returns a cryptographic identity hash for every email. Query your existing database to block users trying to redeem welcome bonuses multiple times.

Automated Enforcement

Stop Trial Abuse Without Blocking Legitimate Users

Configure intelligent signup routing based on identity confidence.

ALLOWFirst-Time Canonical Identity
Grant Full Trial Credits

Canonical email identity has never been seen across your workspace. Grant standard promotional credits or free trial tier.

Platform ActionClean Identity
CHALLENGESubaddress / Salt Detected
Require Card or MFA

User registered using +tagging or dot variations. Require pre-authorization credit card hold or SMS verification before dispensing trial credits.

Platform ActionSalt Churn Detected
DENYDuplicate Identity Hash / Burner
Block Trial Access

Identity hash matches existing trial account or domain is a throwaway burner. Block trial provisioning and route to paid checkout.

Platform ActionAbuse Detected
Filter #1 ➔ Filter #2 HandoffPass ~96.5% clean traffic directly, drop 35% junk at the edge, and only route the ~1% borderline CHALLENGE cases to secondary SMTP checks.
Cuts SMTP bills by up to 40%

Frequently Asked Questions

How do I prevent someone from signing up with [email protected] after using [email protected]?

EmailScore returns a normalized identity_hash and normalized_email field in every API response. By storing or indexing the identity_hash in your users table, a unique database constraint automatically prevents repeat signups from the same underlying mailbox.

Do legitimate users use '+' subaddressing?

Yes, many tech-savvy users use subaddressing for filtering. Rather than outright blocking them, our CHALLENGE tier allows you to welcome the user but withhold automated trial credits until identity verification (like card validation) is completed.

What is the computational overhead on our database?

Zero. EmailScore normalizes the string and generates the SHA-256 fingerprint in memory before your database query is executed, saving you from running expensive regex queries across millions of user records.

Protect Your SaaS Margins

End Free Trial Fraud Today

Stop burning cloud infrastructure and LLM compute on duplicate free trial accounts.