Simple Angular.js contact form example.

contact.html

<div class="col-lg-12 col-md-12 col-sm-12" ng-controller="ContactController">
  <div class="alert alert-danger" ng-show="error">
    <button class="close" data-dismiss="alert">x</button>
    <strong>Error!</strong> An error occured while trying to send message.
  </div>
  <div class="alert alert-success" ng-show="success">
    <button class="close" data-dismiss="alert">x</button>
    <strong>Success! </strong> Your message was successfully sent.
  </div>
  <form role="form" name="contactForm">
    <div class="form-group" ng-class="{error: contactForm.name.$invalid}">
    <label>Full Name</label>
    <input class="form-control" type="text" name="name" ng-model="user.name" required="required" placeholder="Your name">
      <span class="help-block" ng-show="contactForm.name.$error.required">Required</span>
    </div>
    <div class="form-group" ng-class="{error: contactForm.email.$invalid}">
      <label>Email</label>
      <input class="form-control" type="email" name="email" ng-model="user.email" required="required" placeholder="Your email address">
      <span class="help-block" ng-show="contactForm.email.$error.required">Required</span>
      <span class="help-block" ng-show="contactForm.email.$error.email">Invalid email address</span>
    </div>
    <div class="form-group" ng-class="{error: contactForm.message.$invalid}">
      <label>Message</label>
      <textarea class="form-control" rows="5" name="message" ng-model="user.body" required="required" placeholder="Your messsage"></textarea>
      <span class="help-inline" ng-show="contactForm.message.$error.required">Required</span>
    </div>
    <button class="btn btn-primary btn-lg btn-block" ng-click="send()" ng-disabled="contactForm.$invalid">Send</button>
  </form>
</div>

contact.js

function ContactController($scope, $http) {
  $scope.success = false;
  $scope.error = false;
  $scope.send = function () {

  var htmlBody = '<div>Name: ' + $scope.user.name + '</div>' +
                 '<div>Email: ' + $scope.user.email + '</div>' +
                 '<div>Message: ' + $scope.user.body + '</div>' +
                 '<div>Date: ' + (new Date()).toString() + '</div>';
  
    $http({
      url: 'https://api.postmarkapp.com/email',
      method: 'POST',
      data: {
        'From': 'foo@foo.com',
        'To': 'bar@bar.com',
        'HtmlBody': htmlBody,
        'Subject': 'New Contact Form Submission'
      },
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
        'X-Postmark-Server-Token': '8569dcd45-6a1a-4e7b-ae75-ea37629de4'
      }
    }).
    success(function (data) {
    	$scope.success = true;
    	$scope.user = {};
    }).
    error(function (data) {
    	$scope.error = true;
    });
  }
}

Looks like Postmark doesnt support CORS?