如何创建outlook外接程序以显示已发送电子邮件的措施项的已读回执？

using Outlook = Microsoft.Office.Interop.Outlook;
Outlook.Application outlookApp = new Outlook.Application();

Outlook.MAPIFolder sentFolder = outlookApp.Session.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderSentMail);

foreach (Outlook.MailItem mailItem in sentFolder.Items)
{
    // 根据需要的条件筛选邮件项
}

mailItem.ReadReceiptRequested = true;
mailItem.Send();

using Outlook = Microsoft.Office.Interop.Outlook;

namespace OutlookAddIn
{
    public class ReadReceiptAddIn
    {
        public void AddReadReceipt()
        {
            Outlook.Application outlookApp = new Outlook.Application();
            Outlook.MAPIFolder sentFolder = outlookApp.Session.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderSentMail);

            foreach (Outlook.MailItem mailItem in sentFolder.Items)
            {
                // 根据需要的条件筛选邮件项
                if (/* 邮件筛选条件 */)
                {
                    mailItem.ReadReceiptRequested = true;
                    mailItem.Send();
                }
            }
        }
    }
}