See the available authentication methods. If you are using username & password authentication, specify the username to authenticate as. If you are using API Key authentication and you are not using the JSON, Javascript or ADO APIs, use your API Key here with the prefix apikey-, e.g. apikey-ABCD-1234-EFGH-5678

If you are using username & password authentication, specify the password to use for authentication. Otherwise leave this blank.

The email address to validate.

The level to validate the email to. The following values are currently supported:

• Syntax - the supplied email is checked to ensure that it meets the standard email address format.
  This is the quickest option and would reject such incorrect email addresses as "noone@nowhere" and "N/A", but would accept incorrect email addresses that are correctly formed but that do not include a valid domain name such as "noone@data-9.com"
• MX - the supplied email is checked to ensure that the domain name (the part to the right of the @ sign) exists and is set up to receive email.
  This is still normally very quick, but can take a few seconds in some cases. This check would reject incorrectly formatted email addresses in the same way as the Syntax check, and would also reject a misspelled domain name such as "noone@data-9.com". It can also detect when a domain name exists but does not handle email, such as "noone@example.com".
  It does not verify that the part of the email address to the left of the @ sign exists.
• Server - in addition to the MX level checks, validates that at least one of the mail servers advertised for the domain is actually live.
• Address - in addition to the Server level checks, validates that the mail server accepts mail for the full email address.

An array of options that control further details of how this method operates. See the Advanced Options section below, for more information.

If the level parameter is set to MX, the domain does not have any advertised mail servers, and it does have some possible IP addresses, this option determines how validation should proceed.

The default ServerCheck automatically upgrades the validation level to Server to get a more accurate validation result, but causes the request to take longer.

Alternatively the values AssumeValid or AssumeInvalid can be specified to automatically return a Valid or Invalid result respectively in these cases, resulting in a much faster result.

Indicates whether the method call was successful, or if some error occurred. If the Success field is true, the other results described below can be used to get the results of the method. If Success is false, some error occurred in calling the method, such as the authentication failed or the account is out of credits. The details of the error can be obtained from the ErrorMessage field, and any other results should be ignored.

A status code indicating if the email address could be validated. The following values are available:

• Valid - according to the selected level of validation, the email address appears to be valid. This is not an absolute guarantee that emails sent to this address will be delivered and read.
• Invalid - the email address is invalid. This is a definite assessment that emails sent to this address cannot be delivered.
• Inconclusive - a precise Valid or Invalid result could not be determined. This is normally because the server being used for the address being checked did not respond in time, or did not provide sufficient information.
• CatchAll - when performing Address level validation, the mail server was determined as accepting mail for any address provided to it. The address being checked will be accepted, but may be returned later.
• GreyListed - when performing Address level validation, the mail server declined to indicate whether the address was valid or not due to a greylisting rule. Trying to validate the address again in a few minutes may elicit a more accurate response.