Developers

Verify email straight from your code.

A simple REST API that checks real mailboxes and hands back a clear verdict for every address — one at a time or a million at once.

# Verify a single address
curl -X POST https://app.qualisend.com/api/v1/verify \
  -H "Authorization: Bearer qs_live_..." \
  -H "Content-Type: application/json" \
  -d '{"email":"jane@example.com"}'

200 OK · application/json

{
  "email": "jane@example.com",
  "status": "deliverable",
  "reason": "accepted_email",
  "score": 98,
  "sub_flags": { "free_mail": false, "role": false },
  "did_you_mean": null
}

A clear answer, every time

Every address comes back deliverable, risky, undeliverable, or unknown — each with a plain-English reason.

One email or a million

The same simple API handles a single check or a huge list, with results arriving as they land.

Fits your workflow

Get a signed webhook when a job finishes, retry safely with idempotency keys, and copy examples in seven languages.

Just a few endpoints

POST/api/v1/verify— check a single address POST/api/v1/verify/bulk— clean a whole list (CSV or paste)GET/api/v1/jobs/:id?include=results— track a list's progress and pull results GET/api/v1/credits— see how many credits you have left

The full interactive reference — every endpoint, parameter, and response, with copy-paste examples in cURL, Python, JavaScript, PHP, Go, Java, and Ruby — lives in the API reference.

Read the API reference Get an API key