diff --git a/dev/External/User/ko.js b/dev/External/User/ko.js
index d5897ed7a..e56815fe0 100644
--- a/dev/External/User/ko.js
+++ b/dev/External/User/ko.js
@@ -7,6 +7,7 @@ import { isArray } from 'Common/Utils';
 import { EmailAddressesComponent } from 'Component/EmailAddresses';
 import { ThemeStore } from 'Stores/Theme';
 import { moveMessagesToFolder } from 'Common/Folders';
+import { setExpandedFolder } from 'Model/FolderCollection';
 
 const rlContentType = 'snappymail/action',
 
@@ -133,7 +134,7 @@ ko.bindingHandlers.dropmessages = {
 					if (folder && folder.collapsed()) {
 						dragTimer.start(() => {
 							folder.collapsed(false);
-							rl.app.setExpandedFolder(folder.fullName, true);
+							setExpandedFolder(folder.fullName, true);
 						}, 500);
 					}
 				}
diff --git a/dev/Model/FolderCollection.js b/dev/Model/FolderCollection.js
index a53c024f5..f513e7658 100644
--- a/dev/Model/FolderCollection.js
+++ b/dev/Model/FolderCollection.js
@@ -72,6 +72,25 @@ const
 	};
 
 export const
+	/**
+	 * @param {string} sFullName
+	 * @param {boolean} bExpanded
+	 */
+	setExpandedFolder = (sFullName, bExpanded) => {
+		let aExpandedList = Local.get(ClientSideKeyName.ExpandedFolders);
+		if (!isArray(aExpandedList)) {
+			aExpandedList = [];
+		}
+
+		if (bExpanded) {
+			aExpandedList.includes(sFullName) || aExpandedList.push(sFullName);
+		} else {
+			aExpandedList = aExpandedList.filter(value => value !== sFullName);
+		}
+
+		Local.set(ClientSideKeyName.ExpandedFolders, aExpandedList);
+	},
+
 	/**
 	 * @param {?Function} fCallback
 	 */
diff --git a/dev/View/User/MailBox/FolderList.js b/dev/View/User/MailBox/FolderList.js
index fc4166aff..da56f927f 100644
--- a/dev/View/User/MailBox/FolderList.js
+++ b/dev/View/User/MailBox/FolderList.js
@@ -19,31 +19,9 @@ import { showMessageComposer } from 'Common/UtilsUser';
 import { FolderCreatePopupView } from 'View/Popup/FolderCreate';
 import { ContactsPopupView } from 'View/Popup/Contacts';
 
-import { isArray } from 'Common/Utils';
-import { ClientSideKeyName } from 'Common/EnumsUser';
-import * as Local from 'Storage/Client';
-
 import { moveMessagesToFolder } from 'Common/Folders';
 
-/**
- * @param {string} sFullName
- * @param {boolean} bExpanded
- */
-function setExpandedFolder(sFullName, bExpanded) {
-	let aExpandedList = Local.get(ClientSideKeyName.ExpandedFolders);
-	if (!isArray(aExpandedList)) {
-		aExpandedList = [];
-	}
-
-	if (bExpanded) {
-		if (!aExpandedList.includes(sFullName))
-			aExpandedList.push(sFullName);
-	} else {
-		aExpandedList = aExpandedList.filter(value => value !== sFullName);
-	}
-
-	Local.set(ClientSideKeyName.ExpandedFolders, aExpandedList);
-}
+import { setExpandedFolder } from 'Model/FolderCollection';
 
 export class MailFolderList extends AbstractViewLeft {
 	constructor() {