This can be exploited by creating a file together with an OLE object in such a way to cause MAPI to load a DLL from a network share when the OLE object is activated. This issue affects all Outlook versions on Windows 7, Windows 8, Windows 10. A vast community of Microsoft Office365 users that are working together to support the product and others. The settings in the Send/Receive Group windows let you customize the synchronization rate of the new group. To the right of each folder is the Empty drop-down menu which provides options to delete all items in that folder, or items 3 months and older, 6 months and older, and 12 months and older.

In some scenarios, doing so fixes the “Outlook will not open” issue. However, if installing updates doesn’t fix the problem, then try to repair your Office programs. Then, you can try to start Outlook 2016 in Safe Mode and then check which add-in is causing Outlook issues, disabling that add-in.

This happens to accounts that are configured in the iOS Mail app. The loading of unregistered MAPI services has been disabled by default to make Outlook more secure. To access the calendar shared with your Microsoft 365 for business account, you’ll need to accept the invitation from Outlook on the web, iOS, or Android. If you’ve already clicked the Accept button in Outlook 2016, you won’t be able to re-accept the invitation from another Outlook application. The person who sent you the invitation will need to remove your permissions and then send a new invitation. If you typically use an Outlook.com account for email, this issue can occur if there are multiple aliases on the account and the 3rd party email address is the primary alias.

Running the /resetnavpane command removes all customizations to the navigation pane. It’s not uncommon, and you can easily make Microsoft’s email and calendar app open with a few simple fixes. We’ll show you what to do on your Windows 11 or Windows 10 PC.

In the meantime, please use the workarounds suggested for each issue. To edit a shared calendar, go online to your own Outlook.com calendar, open Calendar for Windows 10, or use a mobile device. Read how to Add your Outlook.com account to another mail app. This occurs because custom form script is now disabled by default. To determine the cause of the performance issues, start the Assistant, and run the Outlook Diagnostic in the Advanced Diagnostics section. Serious problems might occur if you modify the registry incorrectly.

Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. To access the tool, open Control Panel and select “Uninstall a Program.” You can start Outlook in safe mode, disable your add-ins, and then try to open Outlook normally.

Having too many shared mailboxes and Fix Outlook Support folders can cause slow performance in Outlook. The limit will depend on the size of the mailboxes and folders. It is recommended to remove any mailboxes that don’t need to be open. You can also add the secondary connected accounts (Gmail, Yahoo, etc.) in Outlook.com as additional accounts in the Outlook profile.

If you are dealing with a broken Outlook, then it doesn’t always mean you need to call tech support or start over from scratch. With the right steps, you can repair Outlook manually and get back to work in no time. You should start with the easy fixes, like repairing Office or turning off add-ins.

Until you can install the Windows Update fix release, you can set a registry key that will cause Outlook to stop using the local Windows Search service. When this registry key is set, Outlook will use its own built-in search engine. The built-in search will display the message below to indicate it is not using the Windows Search service. The issues documented in this section have been reported after installing the recent updates listed below. We’re investigating the issues and will update this page when a fix is available.

Before proceeding to the steps below, consider backing up your Outlook data file. The Inbox Repair tool should also create backups before you begin the repair process. Whether you backed up the data file manually or with the Inbox Repair tool, we recommend remembering the backup location. In the Folder Pane, you might see a folder named Recovered Personal Folders that contains your default Outlook folders or a Lost and Found folder. Although the repair process might recreate some of the folders, they may be empty.

If Outlook is configured to connect to the Exchange mailbox in Online mode, an .ost file is not used. To adjust the number of days of data that are synced for shared folders, add the following registry values. You can limit the synchronization window that’s used for calendar folders to reduce the number of items that are stored locally in your calendar folders.

These issues might occur if a mailbox contains lots of folders or there are lots of items in any one folder. There’s no hard limit to how many folders a mailbox can contain or how many items a folder can contain. However, you might experience decreased performance as the number of items approaches 10,000 calendar items, 10,000 folders, or 100,000 mail items per folder. Large numbers of recurring meetings or long-lived recurring meetings can also have an exaggerated effect on performance. One-time meetings have a relatively small effect, and long-lived, recurring meetings have a greater effect. A change that’s made in an instance of a recurring meeting creates exceptions that are stored in the recurring meeting series.