Extract EML Metadata via C++

// Load from file
System::SharedPtr<MapiMessage> eml = MapiMessage::FromFile(dataDir + L"message.eml");
    
System::String subject;
    
// Access the MapiPropertyTag.PR_SUBJECT property
System::SharedPtr<MapiProperty> prop = eml->get_Properties()->idx_get(MapiPropertyTag::PR_SUBJECT);
    
// If the property is not found, check the MapiPropertyTag.PR_SUBJECT_W (which is a // Unicode peer of the MapiPropertyTag.PR_SUBJECT)
if (prop == nullptr){
    prop = eml->get_Properties()->idx_get(MapiPropertyTag::PR_SUBJECT_W);
}
    
// Cannot found
if (prop == nullptr){
    System::Console::WriteLine(L"No property found!");
    return;
}
    
// Get the property data as string
subject = prop->GetString();
    
System::Console::WriteLine(System::String(L"Subject:") + subject);
// Read internet code page property
prop = msg->get_Properties()->idx_get(MapiPropertyTag::PR_INTERNET_CPID);
if (prop != nullptr){
    System::Console::WriteLine(System::String(L"CodePage:") + prop->GetLong());
}