EWS Digitally signed emails have empty body after upgrade from Exchange 2007 SP1 to Exchange 2013

问题

we have a problem with upgrade from Exchange 2007 SP1 to Exchange 2013. We are using ews to get emails from specific folder. Code looks like this:

private List<Item> GetAllItems(string folderId)
    {
        Folder inbox = Folder.Bind(m_Exchange, folderId);

        List<Item> m_ListOfItems = new List<Item>();
        ItemView itemView = new ItemView(int.MaxValue);

        FindItemsResults<Item> items = inbox.FindItems(itemView);

        foreach (Item item in items)
        {
            item.Load();
            m_ListOfItems.Add(item);
        }

        return m_ListOfItems;
    }

Our problem with Exchange 2013 is when the email is digitally signed, in this case email body is empty. For other emails its just fine for both plaintext/html email types. Also this code works well even for digitally signed emails on Exchange 2007 SP1.

Is anybody familiar with this problem?

Thanks.

来源：https://stackoverflow.com/questions/27149770/ews-digitally-signed-emails-have-empty-body-after-upgrade-from-exchange-2007-sp1