diff --git a/NEWS b/NEWS
index 078e426940..7ab2d5b7ed 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,7 @@ Bug fixes
  - [web] fixed display of notification email in calendar properties
  - [web] fixed display of multi-days events when some weekdays are disabled
  - [web] fixed synchronisation of calendar categories
+ - [web] fixed popup window detection in message viewer (#4518)
 
 4.0.2 (2018-08-24)
 ------------------
diff --git a/UI/WebServerResources/js/Mailer/MailboxController.js b/UI/WebServerResources/js/Mailer/MailboxController.js
index 109a1b62fd..c16bb4db5f 100644
--- a/UI/WebServerResources/js/Mailer/MailboxController.js
+++ b/UI/WebServerResources/js/Mailer/MailboxController.js
@@ -184,8 +184,6 @@
               targetEvent: $event,
               clickOutsideToClose: false,
               escapeToClose: false,
-              scope: $scope,
-              preserveScope: true,
               templateUrl: 'UIxMailEditor',
               controller: 'MessageEditorController',
               controllerAs: 'editor',
@@ -193,6 +191,7 @@
                 return onCompleteDeferred.resolve(element);
               },
               locals: {
+                stateParent: $scope,
                 stateAccount: vm.account,
                 stateMessage: message,
                 onCompletePromise: function () {
diff --git a/UI/WebServerResources/js/Mailer/Mailer.popup.js b/UI/WebServerResources/js/Mailer/Mailer.popup.js
index 0d15541a67..bcfa6ab870 100644
--- a/UI/WebServerResources/js/Mailer/Mailer.popup.js
+++ b/UI/WebServerResources/js/Mailer/Mailer.popup.js
@@ -246,8 +246,6 @@
         disableParentScroll: false,
         clickOutsideToClose: false,
         escapeToClose: false,
-        scope: $scope,
-        preserveScope: true,
         templateUrl: 'UIxMailEditor',
         controller: 'MessageEditorController',
         controllerAs: 'editor',
@@ -255,6 +253,7 @@
           return onCompleteDeferred.resolve(element);
         },
         locals: {
+          stateParent: $scope,
           stateAccount: stateAccount,
           stateMessage: stateMessage,
           onCompletePromise: function () {
diff --git a/UI/WebServerResources/js/Mailer/MessageController.js b/UI/WebServerResources/js/Mailer/MessageController.js
index c772c9d5e0..7dc4b78ec0 100644
--- a/UI/WebServerResources/js/Mailer/MessageController.js
+++ b/UI/WebServerResources/js/Mailer/MessageController.js
@@ -285,8 +285,6 @@
               targetEvent: $event,
               clickOutsideToClose: false,
               escapeToClose: false,
-              scope: $scope,
-              preserveScope: true,
               templateUrl: 'UIxMailEditor',
               controller: 'MessageEditorController',
               controllerAs: 'editor',
@@ -294,6 +292,7 @@
                 return onCompleteDeferred.resolve(element);
               },
               locals: {
+                stateParent: $scope,
                 stateAccount: vm.account,
                 stateMessage: message,
                 onCompletePromise: function () {
diff --git a/UI/WebServerResources/js/Mailer/MessageEditorController.js b/UI/WebServerResources/js/Mailer/MessageEditorController.js
index d0f643a581..1ea00ae1b6 100644
--- a/UI/WebServerResources/js/Mailer/MessageEditorController.js
+++ b/UI/WebServerResources/js/Mailer/MessageEditorController.js
@@ -6,11 +6,12 @@
   /**
    * @ngInject
    */
-  MessageEditorController.$inject = ['$scope', '$window', '$stateParams', '$mdConstant', '$mdUtil', '$mdDialog', '$mdToast', 'FileUploader', 'stateAccount', 'stateMessage', 'onCompletePromise', 'encodeUriFilter', '$timeout', 'sgFocus', 'Dialog', 'AddressBook', 'Card', 'Preferences'];
-  function MessageEditorController($scope, $window, $stateParams, $mdConstant, $mdUtil, $mdDialog, $mdToast, FileUploader, stateAccount, stateMessage, onCompletePromise, encodeUriFilter, $timeout, focus, Dialog, AddressBook, Card, Preferences) {
+  MessageEditorController.$inject = ['$scope', '$window', '$stateParams', '$mdConstant', '$mdUtil', '$mdDialog', '$mdToast', 'FileUploader', 'stateParent', 'stateAccount', 'stateMessage', 'onCompletePromise', 'encodeUriFilter', '$timeout', 'sgFocus', 'Dialog', 'AddressBook', 'Card', 'Preferences'];
+  function MessageEditorController($scope, $window, $stateParams, $mdConstant, $mdUtil, $mdDialog, $mdToast, FileUploader, stateParent, stateAccount, stateMessage, onCompletePromise, encodeUriFilter, $timeout, focus, Dialog, AddressBook, Card, Preferences) {
     var vm = this;
 
     this.$onInit = function() {
+      $scope.isPopup = stateParent.isPopup;
       vm.addRecipient = addRecipient;
       vm.autocomplete = {to: {}, cc: {}, bcc: {}};
       vm.autosave = null;