Email Verification Library for PHP

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.

Getting Started

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

Installation

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.

Usage

<?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("test@example.com");
}
catch (Exception $e) {
  echo "Code: " . $e->getCode() . " Message: " . $e->getMessage();
}

Options

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

// Example with options
$response = $kickbox->verify("test@example.com", array('timeout' => 6000));

Response information

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 (postmaster@example.com, support@example.com, 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. (bill.lumbergh@gamil.com -> bill.lumbergh@gmail.com)
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. (BoB@example.com -> bob@example.com)
user string - The user (a.k.a local part) of the provided email address. (bob@example.com -> bob)
domain string - The domain of the provided email address. (bob@example.com -> 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 = $kickbox->verify('test@example.com');
var_dump($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) "test@example.com"
    '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) {
        ...
      }
    }
  }
}

Response headers

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.

Contributing

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

Testing

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

$ API_KEY=test_feddaddeadbeef1123581321 composer test

License

MIT

Bug Reports

Report here.

Need Help?

help@kickbox.com

kickboxio/kickbox-php