When you write VBA or .NET code to control Outlook (send emails, read calendars, etc.), you add a reference to Microsoft Outlook 16.0 Object Library . This tells your project where to find Outlook’s object model.
A recent Microsoft Office update may have failed or changed the location of the file.
To use this library for automation in Excel, Word, or Access, follow these steps in the Microsoft Visual Basic Editor Open your application (e.g., Excel) and press to open the VBA Editor. References Scroll down to find Microsoft Outlook 16.0 Object Library and check the box. If it's missing from the list: and navigate to the file paths listed above to select MSOUTL.OLB Microsoft Support Important Troubleshooting Notes microsoft outlook 16.0 object library dll download
If you already have Office 16.0 (2016/2019/2021/365) installed but the library is missing, your Office installation may be corrupted.
: If you share a macro-enabled file with someone using an older version of Office (e.g., 2013), the reference may break. Best Practice: Late Binding When you write VBA or
Method 2: Enabling the Reference in VBA (Excel, Access, Word)
The server likely does not have Microsoft Outlook installed. The Outlook Object Library requires Outlook to be installed (and often a mailbox configured). On servers, prefer using Exchange Web Services (EWS) or Graph API instead of the Outlook COM object. To use this library for automation in Excel,
If you are struggling with DLL issues and do not require Outlook’s full UI automation, consider these robust alternatives:
Match the bitness. You cannot cross-bitness communicate via COM. Either:
Instead of downloading a file, you just need to "point" your project to the one already there: Open the (press Alt + F11 in any Office app). Go to Tools > References .