Outlook drag-and-drop .msg files lose message body during conversion, while “Save As” .msg works

[LB-202]

nvironment

Docling Serve: 1.31.0
Source: Microsoft Outlook

Problem

Docling successfully extracts the body from an Outlook message when the message is saved using Outlook's “Save As” function.

However, when an equivalent message is created by dragging the message from the Outlook message list to the Windows file system, Docling recognizes the .msg file but does not extract the message body.

Reproduction

Create a simple Outlook email containing:
TESTCODE: OUTLOOK-DRAG-2026
Save the message using Outlook “Save As” as .msg.
Convert it with Docling → message body is extracted correctly.
Drag the same message from Outlook to the Windows desktop.
Convert the resulting .msg with Docling → message body is empty/null.

The issue is also reproducible when uploading the drag-and-drop-generated .msg directly through the Docling Serve UI, so Open WebUI is not involved.

Expected behavior

Both valid Outlook .msg variants should expose the message body.

I can provide a non-confidential minimal .msg test file generated by Outlook drag and drop if useful.