diff --git a/lib/Autodiscover.php b/lib/Autodiscover.php
--- a/lib/Autodiscover.php
+++ b/lib/Autodiscover.php
@@ -48,6 +48,11 @@
                 $type = 'Microsoft';
                 break;
             }
+            // Microsoft Autodiscover V2
+            elseif (stripos($uri, 'autodiscover.json') !== false) {
+                $type = 'Json';
+                break;
+            }
             // Mozilla Thunderbird (Kmail/Kontact/Evolution)
             else if (strpos($uri, 'config-v1.1.xml') !== false) {
                 $type = 'Mozilla';
@@ -117,6 +122,18 @@
     }
 
     /**
+     * Send 401 Unauthorized to the client end exit
+     */
+    protected function unauthorized($basicauth = true)
+    {
+        if ($basicauth) {
+            header('WWW-Authenticate: Basic realm="'.$_SERVER['HTTP_HOST'].'"');
+        }
+        header('HTTP/1.0 401 Unauthorized');
+        exit;
+    }
+
+    /**
      * Get services configuration
      */
     protected function configure()
@@ -299,7 +316,7 @@
         $entries = $result->entries(true);
         $dn      = key($entries);
         $entry   = $entries[$dn];
-        $result  = array();
+        $result  = array('dn' => $dn);
 
         foreach ($attributes as $idx => $attr) {
             $result[$idx] = is_array($entry[$attr]) ? current($entry[$attr]) : $entry[$attr];
@@ -309,6 +326,39 @@
     }
 
     /**
+     * authenticate a user by his given dn and password
+     */
+    protected function authenticate($dn, $password)
+    {
+        if (empty($this->_ldap_server)) {
+            return false;
+        }
+
+        $ldap = new Net_LDAP3(array(
+            'debug'           => in_array(strtolower($this->conf->get('autodiscover', 'debug_mode')), array('trace', 'debug')),
+            'log_hook'        => array($this, 'ldap_log'),
+            'hosts'           => array($this->_ldap_server),
+            'port'            => $this->_ldap_port,
+            'use_tls'         => $this->_ldap_scheme == 'tls'
+        ));
+
+        // connect to LDAP
+        if (!$ldap->connect()) {
+            $this->error("Storage connection failed");
+            return false;
+        }
+
+        // bind as given userdn
+        if (!$ldap->bind($dn, $password)) {
+            $this->unauthorized();
+            return false;
+        }
+
+        $ldap->close();
+        return true;
+    }
+
+    /**
      * LDAP logging handler
      */
     public function ldap_log($level, $msg)
diff --git a/lib/AutodiscoverJson.php b/lib/AutodiscoverJson.php
new file mode 100644
--- /dev/null
+++ b/lib/AutodiscoverJson.php
@@ -0,0 +1,82 @@
+<?php
+
+/**
+ +--------------------------------------------------------------------------+
+ | Kolab Autodiscover Service                                               |
+ |                                                                          |
+ | Copyright (C) 2011-2014, Kolab Systems AG <contact@kolabsys.com>         |
+ |                                                                          |
+ | This program is free software: you can redistribute it and/or modify     |
+ | it under the terms of the GNU General Public License as published by     |
+ | the Free Software Foundation, either version 3 of the License, or        |
+ | (at your option) any later version.                                      |
+ |                                                                          |
+ | This program is distributed in the hope that it will be useful,          |
+ | but WITHOUT ANY WARRANTY; without even the implied warranty of           |
+ | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the             |
+ | GNU General Public License for more details.                             |
+ |                                                                          |
+ | You should have received a copy of the GNU General Public License        |
+ | along with this program. If not, see http://www.gnu.org/licenses/.       |
+ +--------------------------------------------------------------------------+
+ | Author: Daniel Hoffend <dh@dotlan.net>                                   |
+ +--------------------------------------------------------------------------+
+*/
+
+/**
+ * Autodiscover Service class for Microsoft Autodiscover V2
+ */
+class AutodiscoverJson extends Autodiscover
+{
+
+    public function handle_request()
+    {
+        if (preg_match('|autodiscover.json/v1.0/([^\?]+)|', $_SERVER['REQUEST_URI'], $regs)) {
+            $this->email = $regs[1];
+        }
+
+        Log::debug('Request [json]: ' . $_SERVER['REQUEST_URI']);
+    }
+
+    /**
+     * Generates JSON response
+     */
+    protected function handle_response()
+    {
+        if (strtolower($_GET['Protocol']) == 'activesync'
+            && !empty($this->config['activesync'])
+        ) {
+            if (!preg_match('/^https?:/i', $this->config['activesync'])) {
+                $this->config['activesync'] = 'https://' . $this->config['activesync'] . '/Microsoft-Server-ActiveSync';
+            }
+            $json = array(
+                'Protocol' => 'ActiveSync',
+                'Url' => $this->config['activesync']
+            );
+        }
+        elseif (strtolower($_GET['Protocol']) == 'autodiscoverv1') {
+            $json = array(
+                'Protocol' => 'ActiveSync',
+                'Url' => 'https://' . $_SERVER['HTTP_HOST'] . '/Autodiscover/Autodiscover.xml'
+            );
+        }
+        else {
+            http_response_code(400);
+            $json = array(
+                'ErrorCore' => 'InvalidProtocol',
+                'ErrorMessage' => 'The given protocol value \u0027'
+                    . $_GET['Protocol']
+                    . '\u0027 is invalid. Supported values are \u0027'
+                    . (!empty($this->config['activesync']) ? 'ActiveSync,' : '')
+                    . 'AutodiscoverV1\u0027'
+            );
+        }
+
+        $response = json_encode($json, JSON_PRETTY_PRINT);
+        Log::debug('Response [json]: ' . $response);
+
+        header('Content-Type: application/json; charset=' . Autodiscover::CHARSET);
+        echo $response;
+        exit;
+    }
+}
diff --git a/lib/AutodiscoverMicrosoft.php b/lib/AutodiscoverMicrosoft.php
--- a/lib/AutodiscoverMicrosoft.php
+++ b/lib/AutodiscoverMicrosoft.php
@@ -33,6 +33,7 @@
     const MOBILESYNC_NS = "http://schemas.microsoft.com/exchange/autodiscover/mobilesync/responseschema/2006";
 
     private $type = 'outlook';
+    private $password;
 
     /**
      * Handle request parameters (find email address)
@@ -41,8 +42,15 @@
     {
         $post = $_SERVER['REQUEST_METHOD'] == 'POST' ? file_get_contents('php://input') : null;
 
-        Log::debug('Request [microsoft]: ' . $post);
+        // check for basic authentication
+        Log::debug('Request [microsoft]: Basic Auth Username: ' . ($_SERVER['PHP_AUTH_USER'] ?: 'none'));
+        if (empty($_SERVER['PHP_AUTH_USER']) || empty($_SERVER['PHP_AUTH_PW'])) {
+            $this->unauthorized();
+        }
+        $this->password = $_SERVER['PHP_AUTH_PW'];
 
+        // check for request object
+        Log::debug('Request [microsoft]: ' . $post);
         if (empty($post)) {
             $this->error("Invalid input");
         }
@@ -73,6 +81,11 @@
         catch (Exception $e) {
             $this->error("Invalid input");
         }
+
+        // basic auth username must match with given email address
+        if ($_SERVER['PHP_AUTH_USER'] != $this->email) {
+            $this->unauthorized();
+        }
     }
 
     /**
@@ -80,8 +93,12 @@
      */
     public function handle_response()
     {
-        $method = $this->type . '_response';
+        // authenticate the user found during configure() against ldap
+        if (empty($this->config['dn']) || !$this->authenticate($this->config['dn'], $this->password)) {
+            $this->unauthorized();
+        }
 
+        $method = $this->type . '_response';
         $xml = $this->$method();
         $xml->formatOutput = true;