Mailboxlayer
Email Validation & Verification JSON API
Mailboxlayer is a simple and powerful REST API that offers instant email address validation and verification. It helps developers fight fraudulent users and increase delivery rates by checking syntax, typos, and SMTP records in real-time using a lightweight JSON format.
Real-time verification
Verify the actual existence of an email address using instant MX-record and Simple Mail Transfer Protocol (SMTP) checks. This ensures you only send emails to mailboxes that are active and able to receive messages.
Syntax & typo check
Automatically check email syntax and detect potential typos in the domain name. The API provides “did-you-mean” suggestions (e.g., suggesting “gmail.com” if a user types “gmai.com”) to improve user experience and data quality.
Disposable & free provider detection
Filter out disposable email addresses (e.g., Mailinator) and identify free email providers (e.g., Gmail, Yahoo) instantly. This helps you prevent fraudulent sign-ups and segment your user base effectively.
Quality & deliverability score
Receive a numeric quality score between 0.01 and 1 for every verified email address. This score reflects the quality and deliverability of the email, allowing you to automatically filter “real” users from potential abusers.
256-bit
HTTPS Encryption
100
Free Monthly Requests
JSON
Lightweight Format
24/7
Support
Flexible Plan for Every
Stage of Growth
Syntax & Typo Check
Free & Disposable Provider DB
Quality Score
Real‑time SMTP & MX‑Record Check
Catch‑all Detection
Bulk endpoint (batch)
HTTPS Encryption
Standard Support included
Custom solutions / volume
Free
100 Total Requests.
$0
Starter
5,000 Request/mo.
$14.99/mo.
MOST POPULAR
Professional
50,000 Request/mo.
$74.99/mo.
25 emails
Enterprise
250,000 Request/mo.
$249.99/mo.
100 emails
Custom
Need more? Contact sales for custom needs
Need Clarity? Here Are
the Answers You Might
Be Seeking
What is Mailboxlayer?
What is Mailboxlayer?
Mailboxlayer is a JSON-based REST API that validates and verifies email addresses in real-time. It checks syntax, verifies the existence of the email via SMTP, and filters out disposable or free providers to improve delivery rates.
Is there a free plan available?
Is there a free plan available?
Yes, Mailboxlayer offers a free subscription plan that includes 100 API requests per month. It provides access to all standard validation tools, making it perfect for testing and small-scale applications.
How does the email validation work?
How does the email validation work?
The API performs a multi-stage check: it first validates the email syntax, then checks for valid MX records and SMTP server responses, and finally cross-references the domain against a database of known disposable and free email providers.
What information does the API return?
What information does the API return?
The API returns a detailed JSON object containing the email’s validity status, a quality score (0 to 1), a “did you mean” suggestion for typos, and flags for disposable, role-based, or catch-all addresses.
Can Mailboxlayer detect "catch-all" addresses?
Can Mailboxlayer detect "catch-all" addresses?
Yes, the API can identify if an email domain is configured as a “catch-all” server (one that accepts all emails sent to it, regardless of the recipient). This helps you segment your lists and avoid low-quality leads.
How does pricing scale as my usage grows?
How does pricing scale as my usage grows?
Paid plans start at $9.99/mo for 10,000 requests and scale up to the Enterprise plan with 500,000 monthly requests. Higher-tier plans unlock real-time updates, extended historical data (up to 30+ years), and commercial use rights. You can view pricing features here.
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See Mailboxlayer in Action
See how Mailboxlayer powers CRM systems, marketing
platforms, and user registration flows with reliable real-time email verification.
Mailboxlayer Documentation
Everything you need to integrate in minutes:
quickstart guides, code examples, and full API
reference for JSON responses.
quickstart guides, code examples, and full API
reference for JSON responses.
Trusted by Developers
Worldwide
“The disposable email check is a lifesaver. We cut down on spam signups almost immediately.”
Ricardo Scarr
Marketing Director
“We use the MX record check to clean our mailing lists before sending. Bounce rates dropped significantly.”
Paula Sawell
Head of Marketing
“Documentation is super clean. I connected it to our registration form in an afternoon – it was so quick to implement.”
David Randel
Customer Success Manager
“It’s nice to get a quality score back. We use it to filter out low-quality leads automatically.”
Claire Tabbit
CRM Manager
“Reliable and fast. We haven’t had any issues even during our busy months”
Lauren Jones
Head of Marketing and Communications
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