emailFree tool
Deep email check
Is an email address likely real? We check its format, the provider's username rules, throwaway and role addresses, and the domain's mail records: MX, SPF, DMARC, DKIM, MTA-STS, TLS-RPT and BIMI.
| Check | Result | Details |
|---|
Use it from an assistant or a script
Says how likely an email address is to be real, from its format, the provider's username rules, throwaway and role addresses and the domain's mail records, without sending it anything.
curl "https://email59.com/v1/check?email=someone@example.com"
# {"score": 0-99, "verdict": "likely_valid" | "risky" | "likely_invalid" | "unknown", ...}- MCP tool
check_email (no sign-in needed)onhttps://email59.com/v1/mcp- Limit
- 100 checks a day per IP address without a key; 1,000 a day per account with one. Gmail, Outlook and other big providers skip the DNS part. No email is sent.
- Docs
- email59.com/docs
Use it from your code
The same check is a free API: no key, no sign-up. Limits are in the API docs.
curl -s 'https://email59.com/v1/check?email=sam@example.com'The reply has a score (0 to 99), a verdict (likely_valid, risky, likely_invalid or unknown), a summary and one entry per check in checks. Bots can call the check_email tool on the MCP server without signing in. Details in the docs.
What the checks mean
| Check | What it tells you |
|---|---|
| MX | The domain's mail servers. No MX, a null MX or a missing domain means no mailbox can exist. |
| SPF | Which servers may send mail for the domain. A sign of a domain that is looked after. |
| DMARC | What receivers should do with mail that fails SPF or DKIM: none, quarantine or reject. |
| DKIM | Signing keys for the domain's mail. We try common selectors; others can't be listed. |
| MTA-STS, TLS-RPT, BIMI | Optional extras: forced TLS, TLS reports and a brand logo in inboxes. |
The score is an estimate. A domain with good records can still lack this one mailbox, and some servers accept every address. Only a delivered email proves an address.
Send to addresses you checked
email59 is an email router with a small API for OTP codes, newsletters and alerts. No subscriptions.