# UserCheck > UserCheck is a domain intelligence API. Given an email address or a domain, it returns the signals to block fake signups: disposable email detection, relay and forwarding detection, MX validation, domain age and reputation, and more. Key features: - Disposable email detection with an always up-to-date database - Email forwarding and relay domain detection - MX records validation and mail provider identification (mx_providers) - Public email provider detection (Gmail, Yahoo, etc.) - Spam domain flagging - Domain authority scoring (0–100) - TLD trust scoring (1–5) - SPF and DMARC posture - Email normalization (normalized_email) to catch aliases of the same mailbox - Smart typo suggestions (did_you_mean) - Role account detection (hello@, support@, etc.) - Custom blocklists for blocking specific domains - Gates: A rule-based decision engine for signup fraud prevention, with a REST Management API for gates, rules, and decision logs - Webhooks for real-time notifications - Integrations with WordPress, Laravel, Zapier, and Make ## Docs - [Overview](https://www.usercheck.com/docs/get-started/overview.md): What the API returns and how the documentation is organized - [Quickstart](https://www.usercheck.com/docs/get-started/quickstart.md): Make your first request, read the response, and block a disposable signup - [Environments](https://www.usercheck.com/docs/get-started/environments.md): How production, staging, and development environments separate keys, blocklists, and webhooks - [Credits](https://www.usercheck.com/docs/get-started/credits.md): How credits work, what each request costs, and how usage is tracked ### API Reference - [Introduction](https://www.usercheck.com/docs/api/introduction.md): Base URL, endpoints, authentication, and error format - [Authentication](https://www.usercheck.com/docs/api/authentication.md): How to authenticate API requests - [Domain Endpoint](https://www.usercheck.com/docs/api/domain-endpoint.md): Check if a domain is used for disposable email addresses - [Email Endpoint](https://www.usercheck.com/docs/api/email-endpoint.md): Check if an email address is disposable - [Blocklist Endpoint](https://www.usercheck.com/docs/api/blocklist-endpoint.md): Manage your account's blocklist of domains - [Status Endpoint](https://www.usercheck.com/docs/api/status-endpoint.md): Check your account details, plan information, and current API usage - [Rate Limits](https://www.usercheck.com/docs/api/rate-limits.md): Requests per second allowed on each plan and what happens when you exceed it ### Gates - [Gates](https://www.usercheck.com/docs/gates/overview.md): Rule-based access control to allow, block, or challenge user actions - [Quickstart](https://www.usercheck.com/docs/gates/quickstart.md): Create your first gate, review its rules, and call it from your application - [Rules & Conditions](https://www.usercheck.com/docs/gates/rules-conditions.md): How a gate evaluates its rules, and the fields a condition can check - [Decision Endpoint](https://www.usercheck.com/docs/gates/decision-endpoint.md): Request a decision from a gate to allow, block, or challenge a user action - [Management API](https://www.usercheck.com/docs/gates/management-api.md): Create and manage gates, rules, and decision logs over the REST API - [Errors](https://www.usercheck.com/docs/gates/errors.md): The error envelope every Gates v1 endpoint returns, and the codes it can carry - [Migrate from Email & Domain APIs](https://www.usercheck.com/docs/gates/migrate-from-email-domain.md): Move from the /email and /domain endpoints to Gates - [Migrate from v0 to v1](https://www.usercheck.com/docs/gates/migrate-from-v0.md): Move a Gates integration from the /v0 decision endpoint to the /v1 response shape ### Concepts - [Disposable Domains](https://www.usercheck.com/docs/concepts/disposable.md): What the disposable field means, and why an address can be disposable on a domain that is not - [Relay Domains](https://www.usercheck.com/docs/concepts/relay.md): What email relay and forwarding services are, and how these addresses differ from disposable ones - [Public Domains](https://www.usercheck.com/docs/concepts/public-domains.md): What public_domain identifies, and why an address on a public domain says nothing about the person behind it - [Free Subdomains](https://www.usercheck.com/docs/concepts/free-subdomains.md): What free subdomain and dynamic DNS services are, and why only the names beneath them are flagged - [Spam Domains](https://www.usercheck.com/docs/concepts/spam.md): What the spam field flags, how it differs from disposable, and what a false value does not mean - [Role Accounts](https://www.usercheck.com/docs/concepts/role-accounts.md): What makes an address a role account, and what it implies about who is behind the address - [Email Normalization](https://www.usercheck.com/docs/concepts/email-normalization.md): How several spellings of the same mailbox are folded into one canonical address - [Did You Mean](https://www.usercheck.com/docs/concepts/did-you-mean.md): When did_you_mean returns a suggestion, and why null is the normal value - [MX Providers](https://www.usercheck.com/docs/concepts/mx-providers.md): What the mx_providers field identifies, and what the type and grade values mean - [SPF & DMARC](https://www.usercheck.com/docs/concepts/spf-and-dmarc.md): How a domain's SPF posture and DMARC policy are summarized, and what each value means - [Domain Authority](https://www.usercheck.com/docs/concepts/domain-authority.md): What the domain_authority score measures, and how to read a high or low score - [TLD Trust](https://www.usercheck.com/docs/concepts/tld-trust.md): What the tld_trust score measures and what each level from 1 to 5 means ### Webhooks - [Webhooks Overview](https://www.usercheck.com/docs/webhooks/overview.md): Receive real-time notifications when domains are flagged - [Webhook Events & Payloads](https://www.usercheck.com/docs/webhooks/events.md): Available webhook events and their payload structure - [Webhook Security](https://www.usercheck.com/docs/webhooks/security.md): Verify webhook signatures to ensure authenticity - [Webhook Delivery & Retries](https://www.usercheck.com/docs/webhooks/delivery.md): What counts as a successful delivery, and how retries and duplicates behave ### Integrations - [WordPress Plugin](https://www.usercheck.com/docs/integrations/wordpress.md): Block disposable emails on WordPress registration and comments - [Laravel Package](https://www.usercheck.com/docs/integrations/laravel.md): Validate emails and block disposable domains in Laravel - [Zapier Integration](https://www.usercheck.com/docs/integrations/zapier.md): Automate email validation in thousands of apps - [Make Integration](https://www.usercheck.com/docs/integrations/make.md): Automate email validation workflows in Make ## Guides - [How to Block Disposable Email Addresses](https://www.usercheck.com/guides/how-to-block-disposable-email-addresses.md): Tutorial on blocking temporary email addresses from your platform - [What is Email Forwarding](https://www.usercheck.com/guides/what-is-email-forwarding.md): Understanding email forwarding services and their impact - [How to Prevent Free Trial Abuse](https://www.usercheck.com/guides/how-to-prevent-free-trial-abuse.md): Stop free trial abuse without blocking legitimate users - [The Best GitHub Lists for Disposable Email Domains](https://www.usercheck.com/guides/best-github-lists-for-disposable-email-domains.md): Reviewed and compared the most reliable disposable email domain lists - [How to Normalize Email Addresses](https://www.usercheck.com/guides/how-to-normalize-email-addresses.md): Prevent duplicate accounts by normalizing email addresses - [Using TLDs as a Trust Signal](https://www.usercheck.com/guides/using-tlds-as-a-trust-signal.md): What TLD registration requirements reveal about the entity behind a domain ## Legal - [Terms of Service](https://www.usercheck.com/legal/terms.md): Terms of service - [Privacy Policy](https://www.usercheck.com/legal/privacy.md): Privacy policy - [Data Processing Agreement](https://www.usercheck.com/legal/data-processing-agreement.md): Data processing agreement - [Subprocessors](https://www.usercheck.com/legal/subprocessors.md): List of third-party subprocessors - [Security](https://www.usercheck.com/legal/security.md): Security practices and encryption