Outlook developer tool
OutlookSpy
Inspect Outlook objects, Extended MAPI properties, EWS requests, and Microsoft Graph endpoints directly inside Outlook.
Browse live objects, view property values, invoke methods, monitor events, and see exactly how Outlook stores and exposes message data.
- Outlook 97 through 2024
- Microsoft 365
- 32-bit and 64-bit
- Windows 95 through Windows 11
Something that might be a bit confusing... This is where your good friend Outlook Spy comes in handy.
David Sterling etc. in Inside Microsoft Exchange Server 2007 Web Services
I've used OutlookSpy for quite a while now and I wouldn't live without it. It might not be the best thing since sliced bread, but it comes very close.
Ken Slovak in Exchange and Outlook Magazine
If you want to learn more about the inner workings of MAPI, Outlook Spy is an indispensable tool.
Randy Byrne in Building Applications with Microsoft Outlook 2002, Microsoft Press
Now with Microsoft Graph support
OutlookSpy is a developer and troubleshooting tool for inspecting Outlook data, object models, MAPI properties, EWS requests, and Microsoft Graph endpoints directly from Outlook.
For Extended MAPI developers, OutlookSpy exposes the interfaces Outlook uses internally, making it easier to inspect stores, folders, messages, tables, notifications, and property values.
Run Exchange Web Services operations from the current Outlook context without separate tools or credential prompts: select a message or folder, then use the OutlookSpy ribbon.
For Microsoft 365-hosted mailboxes, OutlookSpy exposes more than 100 Microsoft Graph endpoints, including messages, contacts, calendars, OneDrive, OneNote, licensing, and directory objects.
OutlookSpy supports all versions of Outlook, from 97 to 2024 (both 32-bit and 64-bit), running on any version of Windows, from Windows 95 to Windows 11.
Extended MAPI
Inspect the data Outlook uses internally
Browse MAPI hierarchy, examine properties, monitor Extended MAPI notifications, and see exactly how Outlook data is stored.
Outlook Object Model
Browse live Outlook objects
Open Outlook Object Model objects, inspect properties and methods, browse child objects, and monitor events from the current Outlook context.
Exchange Web Services
Run EWS operations from Outlook
Select a message or folder in Outlook, click an OutlookSpy ribbon button, and work with EWS without external utilities or separate credential prompts.
Microsoft Graph
Use Graph with Outlook-hosted mailboxes
OutlookSpy exposes over 100 Microsoft Graph endpoints for hosted Office 365 mailboxes, including messages, contacts, calendars, OneDrive, OneNote, Licensing, and Active Directory objects.
When Outlook hides the details, OutlookSpy shows you what is really there.