AdxOutlookEvents.ItemSend and Extended MAPI Properties

private void adxOutlookAppEvents1_ItemSend(object sender, ADXOlItemSendEventArgs e)
        {
            try
            {
                Outlook.MailItem itm = null;
                if(e.Item is Outlook.MailItem)
                {
                    // 1. save outlook item & get EntryID
                    String entryID = ""; 
                    itm = (Outlook.MailItem) e.Item;
                    itm.Save();
                    entryID = itm.EntryID;

                    Marshal.ReleaseComObject(itm);

                    // 2. Because of archetectural needs and the need to use our mail object outside of outlook too, we ended up using redemption in our mail-wrapper, doing this:
                    var rdmSession = new Redemption.RDOSession();
                    rdmSession.MAPIOBJECT = AddinModule.CurrentInstance.OutlookApp.Session.MAPIOBJECT;

                    var rMail = rdmSession.GetMessageFromID(entryID);
                    var prop = rMail.UserProperties.Add("someUserProp", Redemption.rdoUserPropertyType.olText);
                    prop.Value = "0";
                    rMail.Save();

                    Marshal.ReleaseComObject(rMail);
                }
            }catch(Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }

private void adxOutlookAppEvents1_ItemSend(object sender, ADXOlItemSendEventArgs e)
{
    try
    {
        if (e.Item is Outlook._MailItem)
        {
            // 1. save outlook item & get EntryID 
            Outlook._MailItem itm = e.Item as Outlook._MailItem;
            itm.Save();
            string entryID = itm.EntryID;

            // Marshal.ReleaseComObject(itm); // DO NOT RELEASE, it is the Add-in Express property

            // 1.1 cancel sending
            e.Cancel = true;
            // TODO: close inspector

            // 2. Because of archetectural needs and the need to use our mail object outside of outlook too, we ended up using redemption in our mail-wrapper, doing this: 
            var rdmSession = RedemptionLoader.new_RDOSession();
            Outlook._NameSpace session = this.OutlookApp.Session;
            rdmSession.MAPIOBJECT = session.MAPIOBJECT;
            Marshal.ReleaseComObject(session);

            var rMail = rdmSession.GetMessageFromID(entryID);
            var prop = rMail.UserProperties.Add("someUserProp", Redemption.rdoUserPropertyType.olText);
            prop.Value = "0";
            rMail.Save();

            // 2.1 send updated email
            rMail.Send();

            Marshal.ReleaseComObject(rMail);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }
}

private void ThisAddIn_Startup(object sender, System.EventArgs e)
{
    Application.ItemSend += Application_ItemSend;
}

private void Application_ItemSend(object Item, ref bool Cancel)
{
    try
    {
        if (Item is Outlook._MailItem)
        {
            // 1. save outlook item & get EntryID 
            Outlook._MailItem itm = Item as Outlook._MailItem;
            itm.Save();
            string entryID = itm.EntryID;

            // 2. Because of archetectural needs and the need to use our mail object outside of outlook too, we ended up using redemption in our mail-wrapper, doing this: 
            var rdmSession = RedemptionLoader.new_RDOSession();
            rdmSession.MAPIOBJECT = this.Application.Session.MAPIOBJECT;

            var rMail = rdmSession.GetMessageFromID(entryID);
            var prop = rMail.UserProperties.Add("someUserProp", Redemption.rdoUserPropertyType.olText);
            prop.Value = "0";
            rMail.Save();

            Marshal.ReleaseComObject(rMail);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }
}