Outlook limits the number of Exchange-based email accounts you can add. The default limit is 10. You can raise this limit by adding a registry key to the Windows Registry.
Note: Editing the Windows Registry should be performed by experienced users.
- Close Microsoft Outlook.
- Open the registry editor. To open the registry editor, click the Windows button at the bottom of the taskbar in Windows (usually located bottom left)
- Type Regedit and open the Registry Editor
- Navigate to the following folder: HKEY_CURRENT_USER\Software\Microsoft\Exchange
On the right hand side panel, Right click and select New -> DWORD (32-bit) Value
- Make its name: maxnumexchange
- Double click on the new key and set the values below:
- Your registry should look like this:
- Close the registry editor and reboot your PC.
- You can now open outlook and add more than 10 exchange accounts.