Mail Verifier

API key v1

Check whether email addresses can actually receive mail.

Verifies addresses by talking to the receiving mail server over SMTP, without sending a message. Send up to ten addresses per request and get a valid or invalid verdict for each.

POST https://api.zactonz.com/mverifier/

Parameters

Name	Type	Description
`key`required	string	Your API key, repeated as a form field. Kept for existing integrations; the `Authorization: Bearer` header is the supported way to authenticate.
`emails`required	string	One or more addresses separated by commas. At most ten per request.

Send parameters as application/x-www-form-urlencoded form fields in the request body.

Response

A verdict per address and the time the check took.

Field	Type	Description
`status`	string	`"200"` on success (a string). See status codes below.
`message`	string \| null	Explanation when the request could not be processed, otherwise `null`.
`mails`	object	Map of address to `valid` or `invalid`.
`ttr`	number	Seconds the verification took.

Status codes

The outcome is reported in the JSON status field. See Errors & status codes for the general rules.

`200`	OK	Processed. If `mails` is absent, `message` explains why (no addresses sent, or more than ten).
`400`	Missing API key	`key` was absent.
`403`	Invalid key	`key` is not recognised.
`406`	Key expired	The key's validity period has ended. Contact support to renew it.

Notes

SMTP verification involves a live conversation with each recipient's mail server, so a request with ten addresses can take tens of seconds. Set your client timeout accordingly.

Some providers accept every address at the SMTP stage (catch-all domains); those come back valid even when the mailbox does not exist.