mailgun_validator.js for email validation

$.fn.mailgun_validator = function(options) {

    return this.each(function() {
        $(this).focusout(function() {

            run_validator($(this).val(), options);
        });

    });
};

function run_validator(address_text, options) {
    // don't run validator without input

    if (!address_text) {
        return;

    }
    // length check

    if (address_text.length > 512) {
        error_message = 'Stream exceeds maxiumum allowable length of 512.';

        if (options && options.error) {
           options.error(error_message);

        }
        else {

            console.log(error_message);
        }

        return;
    }


    // validator is in progress

    if (options && options.in_progress) {
        options.in_progress();

    }
    // require api key

    if (options && options.api_key == undefined) {
        console.log('Please pass in api_key to mailgun_validator.')

    }
    var success = false;


    // make ajax call to get validation results

    $.ajax({
        type: "GET",

        url: 'https://api.mailgun.net/v2/address/validate?callback=?',
        data: { address: address_text, api_key: options.api_key },

        dataType: "jsonp",
        crossDomain: true,

        success: function(data, status_text) {
           success = true;

            if (options && options.success) {
                options.success(data);

            }
        },

        error: function(request, status_text, error) {
            success = true;

            error_message = 'Error occurred, unable to validate address.';
            if (options && options.error) {

                options.error(error_message);
            }

            else {
               console.log(error_message);

            }
        }

    });
    // timeout incase of some kind of internal server error

    setTimeout(function() {
        error_message = 'Error occurred, unable to validate address.';

        if (!success) {
            if (options && options.error) {

                options.error(error_message);
            }

            else {
                console.log(error_message);

            }
        }

    }, 30000);
}

email validation

Here we use an "mailgun_validator.js"  for email validation .  

 //Html Code  
<form>

      <div>

        <label for="email">Email address</label><br>
        <input type="email" name="email" id="email">
        <div id="status"></div>
      </div>
      <div>
        <button type="submit" id="validate_submit">Validate</button>
      </div>
 </form> 
//java script       
            <script src="mailgun_validator.js"></script>

// document ready 

      $(function() {
  // capture all enter and do nothing
        $('#email').keypress(function(e) {
          if(e.which == 13) {
           $('#email').trigger('focusout');
           return false;
          }
        });
 // capture clicks on validate and do nothing
        $("#validate_submit").click(function() {
          return false;
        });
 // attach jquery plugin to validate address
        $('#email').mailgun_validator({
          api_key: 'MAILGUN_PUBKEY', // replace this with your Mailgun public API key
          in_progress: validation_in_progress,
          success: validation_success,
          error: validation_error,
        });
      });
// if email successfull validated

      function validation_success(data) {

        $('#status').html(get_suggestion_str(data['is_valid'], data['did_you_mean']));
      }
 // if email is invalid
      function validation_error(error_message) {
        $('#status').html(error_message);
      }
 // suggest a valid email
      function get_suggestion_str(is_valid, alternate) {
        if (alternate) {
          return '<span class="warning">Did you mean <em>' +  alternate + '</em>?</span>';
        } else if (is_valid) {
          return '<span class="success">Address is valid.</span>';
        } else {
          return '<span class="error">Address is invalid.</span>';
        }
      }
MAILGUN_PUBKEY: pubkey-5ogiflzbnjrljiky49qxsiozqef5jxp7