Email verification API
Check an address with a single HTTP request and get back a status, a score, the reasons and flags for disposable, role and free-provider addresses. Use it on signup forms, in checkout, or in your own scripts.
How it works
- 1
Create a key
Sign up for free, open API keys and create a key. It starts with ev_live_.
- 2
Call the endpoint
Send the address to /api/v1/verify with your key as a bearer token. Use GET with a query string or POST with JSON.
- 3
Act on the result
Read the status (valid, risky, invalid or unknown) and the suggested action. Fix typos with the returned suggestion, and block disposable addresses if you wish.
Why use MailSure for this
Built for signup forms
Responses are fast, and malformed addresses are free to check, so you can validate on every keystroke without burning credits.
Bulk jobs through the same API
Create a job from a list, poll its progress, then page through or download the results as JSON or CSV.
Predictable limits
Up to 50 requests per second per key, with concurrency that scales with your plan, and clear error codes for rate limits and low credits.
See how the price compares in the pricing comparison, or try the free email checker first.
Frequently asked questions
- What does the API return?
- A status, a 0 to 100 score, a list of reasons, the domain and its mail servers, and flags for disposable, role and free-provider addresses, plus a suggested action and a typo suggestion when one applies.
- Is there an MCP server for AI assistants?
- Yes. MailSure runs a remote MCP server so assistants such as Claude can call verify_email, check_domain and account_balance. See the integrations page.
- Are there SDKs?
- There are example snippets for cURL, Node.js, Python and PHP in the documentation, and a WordPress plugin for WooCommerce and form plugins.
- What happens when I run out of credits?
- The API returns a clear 402 error. Your free monthly allowance renews each month.