We have developed an Outlook plugin using C++ and MAPI that interacts with our own server, similar to Microsoft Exchange. The plugin works well, but we are facing an issue with inline images in appointments.

Issue Description:
When we create an appointment with an inline image from the server/backend side, the image displays correctly in Outlook. However, if the appointment is modified from within Outlook, the inline image is replaced with a rectangle.

Questions:
Has anyone encountered a similar issue?
Are there any known solutions to ensure the inline image remains intact after modifying the appointment in Outlook?
Are there specific MAPI properties or methods we should use to maintain the inline image?

Thank you for your assistance!

Steps to Reproduce:

Create an appointment with an inline image from the server/backend.
Open the appointment in Outlook; the image is displayed correctly.
Modify the appointment (e.g., change the time or add a participant) and save.
The inline image is replaced with a rectangle.