diff --git a/src/views/apps.html b/src/views/apps.html
index 92a2f86d0..5050a6aa4 100644
--- a/src/views/apps.html
+++ b/src/views/apps.html
@@ -13,6 +13,10 @@
         </h5>
       </div>
       <div class="modal-body">
+        <p ng-show="appPostInstallConfirm.customAuth && !appPostInstallConfirm.app.manifest.addons.email"></p>
+        <p ng-show="appPostInstallConfirm.app.manifest.addons.email">This app is set up to allow all users with a mailbox on this Cloudron. Login with the email and Cloudron password to access the mailbox.</p>
+        <p ng-show="!appPostInstallConfirm.customAuth && !appPostInstallConfirm.app.manifest.addons.email"> This app is set up to authenticate with the Cloudron User Directory. Cloudron users can login and use {{ appPostInstallConfirm.app.manifest.title }}.</p>
+
         <div ng-bind-html="appPostInstallConfirm.app.manifest.postInstallMessage | postInstallMessage:appPostInstallConfirm.app | markdown2html"></div>
         <div ng-show="appPostInstallConfirm.app.manifest.documentationUrl">
           Please see the <a target="_blank" ng-href="{{appPostInstallConfirm.app.manifest.documentationUrl}}">documentation</a> for more information.
@@ -54,6 +58,10 @@
           If you need further help, refer to Cloudron's <a target="_blank" ng-href="{{ appInfo.app.manifest.forumUrl || 'https://forum.cloudron.io' }}">{{ appInfo.app.manifest.title }} forum section</a>.
         </p>
 
+        <p ng-show="appInfo.customAuth && !appInstall.app.manifest.addons.email"></p>
+        <p ng-show="appInfo.app.manifest.addons.email">This app is set up to allow all users with a mailbox on this Cloudron. Login with the email and Cloudron password to access the mailbox.</p>
+        <p ng-show="!appInfo.customAuth && !appInfo.app.manifest.addons.email"> This app is set up to authenticate with the Cloudron User Directory. Cloudron users can login and use {{ appInfo.app.manifest.title }}.</p>
+
         <a ng-show="appInfo.app.manifest.postInstallMessage" href="" data-toggle="collapse" data-parent="#accordion" data-target="#appinfoPostinstallMessage">
           <i class="fa fa-angle-right"></i>
           First time setup instructions
diff --git a/src/views/apps.js b/src/views/apps.js
index dcb496e07..240c19941 100644
--- a/src/views/apps.js
+++ b/src/views/apps.js
@@ -33,11 +33,13 @@ angular.module('Application').controller('AppsController', ['$scope', '$timeout'
         app: {},
         message: '',
         confirmed: false,
+        customAuth: false,
 
         show: function (app) {
             $scope.appPostInstallConfirm.app = app;
             $scope.appPostInstallConfirm.message = app.manifest.postInstallMessage;
             $scope.appPostInstallConfirm.confirmed = false;
+            $scope.appPostInstallConfirm.customAuth = !(app.manifest.addons['ldap'] || app.manifest.addons['oauth']);
 
             $('#appPostInstallConfirmModal').modal('show');
 
@@ -57,10 +59,12 @@ angular.module('Application').controller('AppsController', ['$scope', '$timeout'
     $scope.appInfo = {
         app: {},
         message: '',
+        customAuth: false,
 
         show: function (app) {
             $scope.appInfo.app = app;
             $scope.appInfo.message = app.manifest.postInstallMessage;
+            $scope.appInfo.customAuth = !(app.manifest.addons['ldap'] || app.manifest.addons['oauth']);
 
             $('#appinfoPostinstallMessage').collapse('hide');
             $('#appInfoModal').modal('show');