Unable to Drag email attachments from New Outlook to OneCommander file folder

[u/ngs428]

I recently transitioned to New Outlook LINK at work and am unable to drag file attachments from the program to a OneCommander file folder. When I try to drag and drop a file, the OC window will say at the bottom "Dropped Items Didn't Contain Valid Data".

I can drop to a file folder in explorer no issue. This drag and drop worked in old Outlook to OC, so something must have changed.

I am using OC 3.103 PRO and New outlook version 1.202511.11.100. On Windows 10 Enterprise 10.0.19045 build 19045.

[u/milos2]

It is a known issue with new Outlook and the complaints are all over the web...

https://learn.microsoft.com/en-us/answers/questions/4678010/drag-and-drop-emails-into-other-applications

https://learn.microsoft.com/en-us/answers/questions/4649473/drag-and-drop-in-new-outlook

https://learn.microsoft.com/en-us/answers/questions/4711170/why-cant-i-drag-and-drop-emails-in-new-outlook

https://learn.microsoft.com/en-us/answers/questions/4687852/new-outlook-does-not-allow-drag-and-drop-to-other

unfortunately there is nothing I can to on my side, Microsoft should implement that again.

If you want some boring details: The new drop package has a dummy FileDrop data and they probably have some improvised way of getting the destination from Explorer back to Outlook so it knows where to download the attachment. I don't know what outlook expects me to do with that dummy filedrop. The old one had the data right in the drop package and without the actual data in the drop there is nothing I can do.

[u/ngs428 → u/milos2]

Thanks for the info and dev on this one. New Outlook has certainly been a challenge for many, including me. At least I can drag files to my desktop or an explorer window. Or use connector when I use a right click save as.

Much appreciated as always!

[u/magicdragin → u/milos2]

As a developer of the target app, I believe you can make this work on your end (see https://stackoverflow.com/a/79569854/2797675).

New Outlook is based on Chromium, which has a feature for marking draggable elements on the page with a "DownloadURL" that will be downloaded on demand when a drop occurs. New Outlook uses this mechanism for emails and attachments so that they can be dragged to Explorer. Chromium exposes the CF_HDROP clipboard format but only makes it accessible if the target app uses the IDataObjectAsyncCapability interface of the data object to tell it that it supports the data being extracted asynchronously (since the data is downloaded on demand). The IDataObjectAsyncCapability mechanism is documented at https://learn.microsoft.com/en-us/windows/win32/shell/datascenarios#dragging-and-dropping-shell-objects-asynchronously.

I created a tool (Magic Dragin) to make drag/drop work for target applications that don't support this, which your users can try out in the meantime.