Please could anybody help me with a problem trying to access a parent
message?

I get an event when an attached message is opened and then need to
open the parent message to read some MAPI properties.

I cannot find a way to access this parent message.

I have both MAPI and the Object Model available where I get my event.
The Object Model Mailitem Parent property appears to be a Folder
rather than the parent message and I do not have the MAPI Parent Key
or Parent Entry Id available on the attached message.

Thanks,
Paul M.