Kickbox determines if an email address is not only valid, but associated with a actual user. Uses include:

• Preventing users from creating accounts on your applications using fake, misspelled, or throw-away email addresses.
• Reducing bounces by removing old, invalid, and low quality email addresses from your mailing lists.
• Saving money and projecting your reputation by only sending to real email users.

To begin, hop over to app.kickbox.com and create a free account. Once you've signed up and logged in, click on API Settings and then click Add API Key. Copy the generated API Key. You'll need it to setup the client as explained below.

You will need PHP 7.4 or higher, some PHP extensions (most notably curl, dom, mbstring if working with the unit tests) and composer.

Support for PHP 7.4 is provided on a legacy branch. See https://www.php.net/supported-versions.php

Make sure you have composer installed.

{
    "require": {
        "kickbox/kickbox": "*"
    }
}

Update your dependencies

$ php composer.phar update

This package follows the PSR-0 convention names for its classes, which means you can easily integrate these classes loading in your own autoloader.

<?php

// This file is generated by Composer
require_once 'vendor/autoload.php';

$client   = new Kickbox\Client('Your_API_Key_Here');
$kickbox  = $client->kickbox();

try {
  $response = $kickbox->verify("[email protected]");
}
catch (Exception $e) {
  echo "Code: " . $e->getCode() . " Message: " . $e->getMessage();
}

timeout integer (optional) - Maximum time, in milliseconds, for the API to complete a verification request. Default: 6000.

// Example with options
$response = $kickbox->verify("[email protected]", array('timeout' => 6000));

A successful API call responds with the following values:

• result string - The verification result: deliverable, undeliverable, risky, unknown
• reason string - The reason for the result. Possible reasons are:
  • invalid_email - Specified email is not a valid email address syntax
  • invalid_domain - Domain for email does not exist
  • rejected_email - Email address was rejected by the SMTP server, email address does not exist
  • accepted_email - Email address was accepted by the SMTP server
  • low_quality - Email address has quality issues that may make it a risky or low-value address
  • low_deliverability - Email address appears to be deliverable, but deliverability cannot be guaranteed
  • no_connect - Could not connect to SMTP server
  • timeout - SMTP session timed out
  • invalid_smtp - SMTP server returned an unexpected/invalid response
  • unavailable_smtp - SMTP server was unavailable to process our request
  • unexpected_error - An unexpected error has occurred
• role true | false - true if the email address is a role address ([email protected], [email protected], etc)
• free true | false - true if the email address uses a free email service like gmail.com or yahoo.com.
• disposable true | false - true if the email address uses a disposable domain like trashmail.com or mailinator.com.
• accept_all true | false - true if the email was accepted, but the domain appears to accept all emails addressed to that domain.
• did_you_mean null | string - Returns a suggested email if a possible spelling error was detected. ([email protected] -> [email protected])
• sendex float - A quality score of the provided email address ranging between 0 (no quality) and 1 (perfect quality). More information on the Sendex Score can be found here.
• email string - Returns a normalized version of the provided email address. ([email protected] -> [email protected])
• user string - The user (a.k.a local part) of the provided email address. ([email protected] -> bob)
• domain string - The domain of the provided email address. ([email protected] -> example.com)
• success true | false - true if the API request was successful (i.e., no authentication or unexpected errors occurred)

An example response would look like:

$response = $kickbox->verify('[email protected]');
var_dump($response);

//Below is an example of what the var_dump($response) looks like:

class Kickbox\HttpClient\Response#29 (3) {
  public $body =>
  array(13) {
    'result' =>
    string(11) "deliverable"
    'reason' =>
    string(14) "accepted_email"
    'role' =>
    bool(false)
    'free' =>
    bool(true)
    'disposable' =>
    bool(false)
    'accept_all' =>
    bool(false)
    'did_you_mean' =>
    NULL
    'sendex' =>
    int(1)
    'email' =>
    string(20) "[email protected]"
    'user' =>
    string(9) "test"
    'domain' =>
    string(10) "example.com"
    'success' =>
    bool(true)
    'message' =>
    NULL
  }
  public $code =>
  int(200)
  public $headers =>
  class Guzzle\Http\Message\Header\HeaderCollection#40 (1) {
    protected $headers =>
    array(11) {
      'server' =>
      class Guzzle\Http\Message\Header#41 (3) {
        ...
      }
      'date' =>
      class Guzzle\Http\Message\Header#42 (3) {
        ...
      }
      'content-type' =>
      class Guzzle\Http\Message\Header#43 (3) {
        ...
      }
      'content-length' =>
      class Guzzle\Http\Message\Header#44 (3) {
        ...
      }
      'connection' =>
      class Guzzle\Http\Message\Header#45 (3) {
        ...
      }
      'cache-control' =>
      class Guzzle\Http\Message\Header\CacheControl#46 (4) {
        ...
      }
      'pragma' =>
      class Guzzle\Http\Message\Header#47 (3) {
        ...
      }
      'expires' =>
      class Guzzle\Http\Message\Header#48 (3) {
        ...
      }
      'x-kickbox-balance' =>
      class Guzzle\Http\Message\Header#49 (3) {
        ...
      }
      'set-cookie' =>
      class Guzzle\Http\Message\Header#50 (3) {
        ...
      }
      'x-kickbox-response-time' =>
      class Guzzle\Http\Message\Header#51 (3) {
        ...
      }
    }
  }
}

Along with each response, the following HTTP headers are included:

• X-Kickbox-Balance - Your remaining verification credit balance (Daily + On Demand).
• X-Kickbox-Response-Time - The elapsed time (in milliseconds) it took Kickbox to process the request.

Notify us via app.kickbox.com if issues or PRs require prompt attention. Include a link!

Unit tests should be run using a sandbox key only. You can specify this on the command line:

$ API_KEY=test_feddaddeadbeef1123581321 composer test

MIT

Report here.

[email protected]