Is there a way to obtain a (unique) inbox id by the mail item, maybe over one of the mailitem properties:
https://msdn.microsoft.com/en-us/library/microsoft.office.interop.outlook.mailitem_properties.aspx
I have in my Outlook 2010 a mail that was moved in the deleted items folder. Now I am looking for the source where did it come from (my private inbox or the shared inbox).