diff --git a/email.module b/email.module
index a33d85c..6a7f7c9 100644
--- a/email.module
+++ b/email.module
@@ -150,7 +150,10 @@ function email_field_widget_info() {
     'email_textfield' => array(
       'label' => t('Text field'),
       'field types' => array('email'),
-      'settings' => array('size' => 60),
+      'settings' => array(
+        'size' => 60,
+        'autocomplete' => FALSE,
+      ),
     ),
   );
 }
@@ -169,6 +172,12 @@ function email_field_widget_settings_form($field, $instance) {
     '#required' => TRUE,
     '#element_validate' => array('_element_validate_integer_positive'),
   );
+  $form['autocomplete'] = array(
+    '#type' => 'checkbox',
+    '#title' => t('Autocomplete with users\' email addresses'),
+    '#description' => t('Autocomplete with emails from users of this site.'),
+    '#default_value' => $settings['autocomplete'],
+  );
   return $form;
 }
 
@@ -183,6 +192,7 @@ function email_field_widget_form(&$form, &$form_state, $field, $instance, $langc
     '#size' => $instance['widget']['settings']['size'],
     '#prefix' => '<div class="text-full-wrapper">',
     '#suffix' => '</div>',
+    '#autocomplete_path' => empty($instance['widget']['settings']['autocomplete']) ? '' : 'email-autocomplete',
   );
   return $element;
 }
@@ -199,6 +209,12 @@ function email_menu() {
     'access arguments' => array('access content'),
     'type' => MENU_CALLBACK,
   );
+  $items['email-autocomplete'] = array(
+    'title' => 'Autocomplete for Emails',
+    'page callback' => '_email_siteusers_autocomplete',
+    'access arguments' => array('administer users'),
+    'type' => MENU_CALLBACK,
+  );
   $items['admin/config/content/email'] = array(
     'title' => 'Email Contact Form Settings',
     'description' => 'Administer flood control settings for email contact forms',
@@ -211,6 +227,28 @@ function email_menu() {
 }
 
 /**
+ * Autocomplete sit site's users' emails.
+ */
+function _email_siteusers_autocomplete($string = '') {
+  $matches = array();
+  if ($string != '') {
+    $result = $query = db_select('users', 'u')
+      ->fields('u', array('uid', 'mail'))
+      ->where("LOWER(u.mail) LIKE :mail", array(':mail' => strtolower($string) . '%'))
+      ->range(0, 10)
+      ->execute()
+      ->fetchAllKeyed();
+    $users = user_load_multiple(array_keys($result));
+    foreach ($result as $uid => $mail) {
+      if ($users[$uid]) {
+        $matches[$mail] = check_plain($mail . ' (' . format_username($users[$uid]) . ')');
+      }
+    }
+  }
+  drupal_json_output($matches);
+}
+
+/**
  * Access callback for the email contact page.
  *
  * Checks whether the current user has view access to the entity. Access checks