Email Validator

Verify email address deliverability with syntax check, MX record validation, and SMTP verification. Free email checker to detect disposable, invalid, and risky addresses.

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APIPOST /api/v1/email/validate
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Try also: MX Lookup
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Key Features

100% Free

No registration required, unlimited checks

Instant Results

Real-time analysis with detailed output

REST API Access

Integrate into your workflow via API

Accurate Data

Live queries to authoritative sources

What is Email Validator?

The email validator performs comprehensive multi-step verification to determine whether an email address is valid, deliverable, and safe to send to. The verification process includes four stages: syntax validation (checking the address format conforms to RFC 5322), domain verification (confirming the domain exists and has valid MX records for receiving email), SMTP-level verification (connecting to the mail server to check if the specific mailbox exists without sending an actual email), and risk assessment (detecting disposable/temporary email providers, role-based addresses like info or admin, and known spam traps). This free email verification tool is essential for marketers cleaning email lists before campaigns to reduce bounce rates, SaaS platforms validating user registrations to prevent fake signups, e-commerce sites verifying customer emails to ensure order confirmations reach recipients, sales teams validating prospect emails before outreach, and any application that collects email addresses and needs to ensure data quality.

How to Use

  1. 1Enter the email address you want to validate (e.g., john.doe at example.com)
  2. 2Click 'Run Check' to start the multi-step verification process
  3. 3Review each verification step: syntax check, domain/MX validation, SMTP mailbox check, and risk assessment
  4. 4Check the overall result: deliverable (safe to send), risky (may bounce or be a trap), or invalid (will definitely bounce)
  5. 5Look for warnings about disposable email providers, role-based addresses, or catch-all domains

Who Uses This

System Administrators

Monitor and troubleshoot infrastructure

Developers

Debug network issues and integrate via API

SEO Specialists

Verify domain configuration and performance

Security Analysts

Audit and assess network security

Frequently Asked Questions

How do I verify if an email address is valid and can receive emails?
Enter the email address in the validator and click Run Check. The tool performs four verification steps: first, it checks that the address format is syntactically correct (proper use of characters, single at-sign, valid domain). Second, it queries DNS to verify the domain exists and has MX records pointing to active mail servers. Third, it connects to the mail server via SMTP and checks whether the specific mailbox exists. Fourth, it assesses risk factors like disposable email providers and role-based addresses. The combined result tells you whether the address is safe to send to.
What is a disposable email address and why should I detect them?
A disposable email address is a temporary, throwaway email from services like Mailinator, Guerrilla Mail, Temp Mail, or 10MinuteMail. These addresses work briefly then expire or are abandoned. Users commonly create them to bypass registration forms, access gated content without providing their real email, or engage in fraudulent activity. Detecting and blocking disposable emails is important because they lead to zero engagement, inflate your email list with fake users, and can trigger spam traps that damage your sender reputation.
What is SMTP verification and how does it work?
SMTP verification connects to the recipient's mail server and simulates the beginning of an email delivery — it sends EHLO, MAIL FROM, and RCPT TO commands to check if the server accepts the recipient address. The server responds with either a 250 (address accepted) or 550 (user unknown) code. This is done without actually sending an email. SMTP verification is the most reliable way to check if a specific mailbox exists, though some servers (like Gmail) accept all RCPT TO commands regardless (catch-all behavior), making it impossible to distinguish valid from invalid addresses on those servers.
What is a catch-all domain and why does it affect validation?
A catch-all domain is configured to accept email sent to any address at that domain — whether it exists or not. For example, if example.com is catch-all, both valid-address and nonexistent-address would be accepted by the mail server. This means SMTP verification returns 'valid' for every address on that domain, even fake ones. The email validator detects catch-all domains and flags them as 'risky' since individual address validity cannot be confirmed. About 20-30% of business domains use catch-all configurations.
Why is my bounce rate high even after validating emails?
Several factors can cause bounces even with validated addresses: the mailbox was valid when checked but has since been deleted or deactivated (validate close to send time), the receiving server accepted the RCPT TO but has full-mailbox or quota-based rejection after accepting delivery, the domain uses greylisting (temporarily rejects first delivery attempt), or your sending IP has a poor reputation causing receiving servers to reject your emails regardless of address validity. To minimize bounces, validate immediately before sending, maintain consistent sending patterns, and monitor your sender reputation.

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API Endpoint

POST /api/v1/email/validate
View Documentation