Email Validation

Check email syntax, mail-server records, disposable domains, role addresses and likely typos. Returns checks without confirming a mailbox exists.

Free to try Pay by wallet (x402) email-validate

Example

Example answer

{
  "email": "test@google.com",
  "valid": true,
  "domain": "google.com",
  "mx_records": [
    "smtp.google.com"
  ],
  "format_valid": true,
  "is_disposable": false,
  "has_mx_records": true,
  "is_role_address": false,
  "is_free_provider": false
}

Try it

Runs the real tool from your browser, with no key. Free calls are limited to 300 a month across all free tools.

Inputs (JSON)

{
  "email": "clearly-invalid"
}

Edit the values, then run.

Inputs

Field	Type	Required	What it is
`email`	string	Yes	Email address to validate

Output fields

How reliably each field appears in a successful answer.

Field	Type	Appears
`email`	string	Always (present in every successful answer)
`valid`	boolean	Always (present in every successful answer)
`is_disposable`	boolean	Usually (present for most inputs)
`has_mx_records`	boolean	Usually (present for most inputs)
`is_role_address`	boolean	Usually (present for most inputs)
`format_valid`	—	Always (present in every successful answer)
`is_free_provider`	—	Usually (present for most inputs)
`mx_records`	—	Usually (present for most inputs)
`domain`	—	Usually (present for most inputs)
`reason`	—	Sometimes (present only for some inputs)
`did_you_mean`	—	Sometimes (present only for some inputs)

How to call it

The same tool through each route. MCP clients reach it through Strale’s server at https://api.strale.io/mcp; the call below is what the agent sends.

# Free tool: works without a key, within a monthly allowance. Add your key for more.
curl -X POST https://api.strale.io/v1/do \
  -H 'Content-Type: application/json' \
  -d '{
    "capability_slug": "email-validate",
    "inputs": {
      "email": "clearly-invalid"
    },
    "max_price_cents": 3
  }'

{
  "tool": "strale_execute",
  "arguments": {
    "slug": "email-validate",
    "inputs": {
      "email": "clearly-invalid"
    },
    "max_price_cents": 3
  }
}

import { Strale } from "straleio";

const strale = new Strale({ apiKey: process.env.STRALE_API_KEY! });
const result = await strale.do({
  capability_slug: "email-validate",
  inputs: {
    "email": "clearly-invalid"
  },
  max_price_cents: 3,
});

import os
from straleio import Strale, DoRequest

strale = Strale(api_key=os.environ["STRALE_API_KEY"])
result = strale.do(DoRequest(
    capability_slug="email-validate",
    inputs={
        "email": "clearly-invalid",
    },
    max_price_cents=3,
))

# No account. The first request answers 402 with the price in USDC;
# an x402 client pays it from your wallet and repeats the request.
curl -i 'https://api.strale.io/x402/v2/email-validate?email=clearly-invalid'

Limitations

New disposable domains can be missed
Disposable email detection covers major providers but new throwaway domains may not be flagged
What to do instead: Check the domain’s age when investigating suspicious traffic.
A valid result does not prove the mailbox exists
No mailbox is contacted. A made-up or bouncing address can return valid if its syntax is correct, its domain has mail servers, and it is not flagged as disposable. Catch-all domains are one example; mailbox existence and delivery are never checked.
What to do instead: Require confirmation through a verification link before relying on a mailbox.