The Sendbound Email Verification API
Validate email addresses before you send — catch typos, disposable addresses, and role accounts before they hurt your sender reputation.
Every invalid email address you send to is a small tax on your sender reputation. Enough of them and Gmail, Yahoo, and Outlook start treating all of your mail with suspicion — not just the mail to bad addresses. Sendbound's new Email Verification API lets you validate addresses before you ever touch the send button.
What it checks
The API runs a seven-layer check against every address you submit. It starts with syntax validation, then MX record resolution, then SMTP reachability testing (without sending a real email). On top of that, it cross-references three databases: a disposable domain list with 42,000+ entries, a role-account list (postmaster@, no-reply@, abuse@), and a typo-correction engine that catches common misspellings of major email providers.
How to use it
The API is a single endpoint. POST an email address and get back a JSON object with a `valid` boolean, a `confidence` score from 0–100, and a breakdown of which checks passed and failed. You can call it at signup, before a campaign send, or in bulk via the batch endpoint that processes up to 5,000 addresses per request.
"We ran verification on our entire list before our last campaign. Removed 12% of addresses. Inbox placement jumped from 91% to 98.4% overnight."
Pricing
Email verification is included in all paid Sendbound plans at no extra cost. Free plan users get 500 verifications per month. If you need to verify a large list, the bulk endpoint is available on Scale plans and above.