The Fastest Way To Validate Emails
Protect your sender reputation and boost deliverability with our advanced email verification API. Validate emails instantly with 99.9% accuracy.
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Powerful Features for Email Verification
Everything you need to validate emails and protect your sender reputation
Real-Time Verification
Verify emails instantly with sub-100ms response times. Integrate seamlessly into your signup flows.
Syntax & Domain Check
Validate email format, DNS records, and MX servers to ensure deliverability.
Disposable Email Detection
Identify and block temporary, disposable, and trash email addresses automatically.
Catch-All Detection
Detect catch-all domains that accept all emails, reducing false positives.
Risk Scoring
Get detailed risk scores and insights for each email address verified.
Global Coverage
Verify emails from any country with our worldwide infrastructure.
Bulk Verification
Upload and verify thousands of emails at once with our bulk API.
Developer-Friendly
RESTful API with SDKs for Node.js, Python, PHP, Ruby, and more.
GDPR Compliant
Fully compliant with GDPR and international privacy regulations.
Real-Time Verification Engine
Our multi-layer verification process ensures maximum accuracy
Drop CSV, XLS, XLSX, or paste a JSON array. Returns a batchId in under
100 ms — even for 500 MB files.
Streams in 500-row chunks, writes Email Records to Postgres, fans Gmail and non-Gmail jobs into separate BullMQ queues.
Gmail: up to 10 RCPT TO per TCP session, optionally via SOCKS5 proxies. Others: MillionVerifier atm 300 jobs/min, 20× concurrency.
Every email gets a status, quality tier (good/bad/unknown), 0–100 score, and a reason. Export filtered results as CSV or JSON.
Simple, Pay-As-You-Go
Credits That Never Expire
Get started quickly with our simple RESTful API. SDKs available for all major programming languages.
Trusted By Email Marketers Worldwide
Real feedback from businesses using Quest to clean lists and reduce bounce rates.
Great value for the money. We've been using this service for years and the reliability has been outstanding.
Frank Tolve
Email Marketing Manager
Does exactly what it says. Price wise, it's the best-priced on the market and can handle very large bulk requests reliably.
Christopher Penn
Digital Marketing Director
Excellent service! Simple interface. Email validation is fast and accurate with reasonable prices. Extremely satisfied.
Mira I.
CRM Specialist
Common Questions Answered
Everything you need to know about verification, credits, exports, and deliverability.
Quest accepts CSV, XLS, and XLSX files up to 500 MB, plus raw JSON arrays via the API. CSV column auto-detection supports headers like and falls back to the first column. Excel files are streamed via ExcelJS so even 500 MB files process without timeouts.
Quest opens a direct TCP connection to Gmail's MX servers and sends up to 10 RCPT TO commands per session, optionally routing traffic through SOCKS5 proxies to avoid IP-based rate limits. Each SMTP response code is mapped to a verification status — valid, invalid, or unknown.
VALID means the mailbox exists and accepted our probe. INVALID means it was explicitly rejected by the server. UNKNOWN means the server returned a catch-all response, timed out, or we couldn't complete the SMTP handshake — these are scored separately so you can decide how to treat them.
No. Credits you purchase never expire. They roll over indefinitely and are consumed only when a verification completes successfully.
Once a batch finishes processing, you can download the full results as CSV or JSON from the dashboard. You can also filter by status (valid, invalid, unknown) before exporting so you only download the rows you need.
Payments are processed securely via Stripe. We support all major credit and debit cards. Invoices are emailed automatically after each purchase and are available in your billing dashboard at any time.
Get In Touch With Quest
Have questions? We'd love to hear from you. Send us a message and we'll respond as soon as possible.
Contact Information
naymurrahman056@gmail.com
Phone
+880 1644 918 439
Location
San Francisco, CA United States
Need Quick Help?
Talk directly with the Quest Verify team on WhatsApp for instant support, live product guidance, and personalized solutions tailored to your email verification workflow.