Is it possible to drag an attachment or e-mail to an Outlook Web-Addin. The add-in is available to either Outlook 365 (Web) or the main client
My assumption is no - as it is a sandboxed boundary, but I have heard about people running applications in the system tray to intercept the mouse drag event?
Is this viable? are there any security risks with this approach?
Thank you Rich
System tray interception is not a viable solution, not only because of security concerns, but because of deployment reasons. Add-ins functionality and entry points should be entirely described by their manifest files and should not require the user to install any background process.
As to drag-and-drop support in general, currently drag-and-drop to the sandbox is not a part of the product. However, we track Outlook add-in feature requests on our user-voice page. Please add your request there. Feature requests on user-voice are considered when we go through our planning process.
来源：https://stackoverflow.com/questions/51288689/drag-and-drop-between-outlook-and-add-in-pane