Overview
Theemail_score is computed by analyzing various characteristics of both the email address and its associated domain. We run comprehensive checks on the domain to understand its trustworthiness and combine that with detailed analysis of the email structure and history to create a single score.
The scoring process involves:
- Domain Intelligence - Analyzing the domain’s web presence, business metadata, and reputation
- Email Intelligence - Examining email structure, deliverability, and breach history
- Signal Aggregation - Combining all signals into a unified risk assessment
email_score in our API, where the score ranges from -1 to 1:
- -1 represents the most trustworthy emails
- 1 represents the highest risk emails
Score Examples
High Trust (-1.0)
johndoe@gmail.comTrust Signals: email_age_greater_than_5_years, email_known_online_history
Neutral (0.0)
john@verisoul.aiNo particular risk or trust indicators detected, representing a neutral assessment.
High Risk (1.0)
confidentialbot+1232384uu8734587@tempmail.comRisk Signals: email_alias, email_likely_generated, email_high_number_count, domain_disposable_type
Domain Intelligence
Web Presence Analysis
We evaluate how the domain appears in search engines and assess its overall online footprint and reputation.
Content Quality Assessment
Our systems analyze the domain’s landing page content, design quality, and professional appearance indicators.
Business Verification
For business domains, we cross-reference public company data including employee count, registration details, and legitimacy markers.
Technical Infrastructure
We examine the domain’s technical setup, including MX record configuration, DNS health, and email delivery infrastructure.
Domain Account Velocity
Thenum_account_from_domain field helps you detect and block high-velocity domains that may be used for signup abuse or free trial fraud. This field counts how many accounts with the same apex domain as the current account have been seen in your project.
Real-Time Calculation: This count is calculated in real-time on every API call, so it always reflects the most up-to-date value.
- Apex Domain Matching: The count is performed at the apex domain level, meaning subdomains are included. For example,
user@mail.company.comanduser@company.comwould both count toward thecompany.comapex domain. - Project Scoped: The count only includes accounts within your specific project.
- Capped at 1000: If the returned value is 1000, you can assume there are at least 1000 accounts from that domain in your project. The count is capped for performance reasons.
- Always Available: This field is returned on every API call, even before the full email intelligence scoring is complete.
num_account_from_domain in combination with domain_type to identify suspicious signup patterns:
- If
num_account_from_domain> X anddomain_typenot in{personal, relay}→ consider blocking or requiring additional verification - Set X to a threshold reasonable for your user base (e.g., 5-10 for most B2B applications)
Email Intelligence
Our comprehensive email analysis examines multiple dimensions of the email address to determine authenticity and risk:Email Structure Analysis
Email Structure Analysis
Username Pattern Recognition: We analyze the composition of email usernames, including the frequency of periods, numbers, and numeric blocks that may indicate automated generation or suspicious patterns.Format Validation: Our systems detect unusual character combinations, suspicious formatting patterns, and other indicators that suggest machine-generated or fraudulent email addresses.
Security & Breach History
Security & Breach History
Data Breach Intelligence: We maintain an extensive database of known data breaches and check whether the email address has appeared in previous security incidents.Risk Assessment: Each breach is categorized by severity and type, allowing us to assess the overall risk profile associated with the email’s exposure history.
Deliverability & Validation
Deliverability & Validation
Real-time Validation: We perform live checks to verify whether the email address can actually receive messages and is actively monitored.Mailbox Health: Our system monitors for delivery issues, full mailboxes, and other factors that might affect email deliverability and user engagement.
Timing
For the most accurate email score, the scoring runs asynchronously. For non-personal emails (business, education, relays, governments, etc.), if Verisoul has seen the domain before, you can expectemail_score to be complete and included in the overall score on the first request.
For personal domains or any domains new to Verisoul, the email_score will be updated asynchronously and account(s) will be automatically repredicted for you.
You can determine the score is complete when email_score is non-null, which typically takes about 3–5 seconds after we first observe the email.
Signals
Our email intelligence generates various trust and risk signals that contribute to the overall email score. These signals are categorized into risk indicators and trust indicators to provide a comprehensive assessment.The Identity Intelligence column marks signals returned only by the standalone Email Intelligence API when Identity Intelligence is enabled (
identity_intelligence: true). All other signals are returned by both the real-time /session/authenticate call and the Email Intelligence API. Identity match/mismatch signals also require the relevant claim (name, phone, or country) to be supplied.