When impersonating and making a change on an item in an folder where the user lacks permissions, the change is undone and a notification is sent by email.
Atm ReplyBackImExporter->sendNotificationEmail() gets the AdditionalFolders to get the folder name and use it in the email.
When impersonating, the AdditionalFolders is empty and so the folder not found.
Ideally we would get the hierarchy cache (is it loaded?) to retrieve the folder name, or get it directly from the MAPIProvider->GetFolder().