how to find mail that was send by MailItem.Display()

Question

I have following requirement :

• Allow the user to drag & drop an email from outlook to a datagrid
• Prepare a reply mail, and show it so the user can review and send
• After sending, also fetch the send mail and put it into the datagrid

The drag/drop I have working
Preparing the replay email and showing it to the user I also have working, with this code :

MailItem mail = GetMailBySubject(dateReceived, subject);
if (mail != null)
{
    MailItem mailReply = mail.ReplyAll();
    // add text and stuff to mailReply...
    mailReply.Display();
}

This will open a window in outlook, as if the user clicked reply in outlook.

Now I am stuck with the 3th requirement,
after the user send the reply email, I need somehow to find this email in outlook to add it to my datagrid.

But I have no clue on how to do that.
All I have is the original mail that is been used to prepare the reply.
Is there a way to find the reply with only this, or is this maybe a complete wrong approach ?
To make it more difficult is that I have to show the reply email NON Modal, so I have no trigger when the user clicked on send in outlook.

for reference, here is the code for GetMailBySubject

private MailItem GetMailBySubject(DateTime dateReceived, string subject)
{
    MailItem Result = null;

    Microsoft.Office.Interop.Outlook.Application OutlookIns = new Microsoft.Office.Interop.Outlook.Application();
    Microsoft.Office.Interop.Outlook.NameSpace olNamespace = OutlookIns.GetNamespace("MAPI");
    MAPIFolder myInbox = olNamespace.GetDefaultFolder(OlDefaultFolders.olFolderInbox);

    Items items = myInbox.Items;
    int count = items.Count;
    MailItem mail = null;
    int i = 1; //DO NOT START ON 0

    while ((i < count) && (Result == null))
    {
        if (items[i] is MailItem)
        {
            mail = (MailItem)items[i];
            if ((mail.ReceivedTime.ToString("yyyyMMdd hh:mm:ss") == dateReceived.ToString("yyyyMMdd hh:mm:ss")) && (mail.Subject == subject))
            {
                Result = mail;
            }
        }
        i++;
    }

    return Result;
}

EDIT
I tried this code as suggested, but the Items.ItemAdd event is not firing.
So I must still be doing something wrong but I cant see it

this is my code now

MailItem mail = GetMailBySubject((DateTime)sentOn, msg.Subject);
if (mail != null)
{
    MailItem mailReply = mail.ReplyAll();
    mailReply.HTMLBody = GetDefaultReplyText() + Environment.NewLine + mailReply.HTMLBody;

    Guid guid = Guid.NewGuid();
    UserProperties mailUserProperties = null;
    UserProperty mailUserProperty = null;

    mailUserProperties = mailReply.UserProperties;
    mailUserProperty = mailUserProperties.Add("myproperty", OlUserPropertyType.olText);
    mailUserProperty.Value = guid.ToString(); ;
    // the code below gives error "The property cannot be parsed or has an invalid format"
    //mailReply.PropertyAccessor.SetProperty("myproperty", guid.ToString());

    mailReply.Display();
}


private MailItem GetMailBySubject(DateTime dateReceived, string subject)
{
    MailItem Result = null;

    Microsoft.Office.Interop.Outlook.Application OutlookIns = new Microsoft.Office.Interop.Outlook.Application();
    Microsoft.Office.Interop.Outlook.NameSpace olNamespace = OutlookIns.GetNamespace("MAPI");
    MAPIFolder myInbox = olNamespace.GetDefaultFolder(OlDefaultFolders.olFolderInbox);

    Items items = myInbox.Items;
    int count = items.Count;
    MailItem mail = null;
    int i = 1; //DO NOT START ON 0

    while ((i < count) && (Result == null))
    {
        if (items[i] is MailItem)
        {
            mail = (MailItem)items[i];
            if ((mail.ReceivedTime.ToString("yyyyMMdd hh:mm:ss") == dateReceived.ToString("yyyyMMdd hh:mm:ss")) && (mail.Subject == subject))
            {
                Result = mail;
                MAPIFolder mySent = olNamespace.GetDefaultFolder(OlDefaultFolders.olFolderSentMail);
                mySent.Items.ItemAdd += Items_SentMailItemAdd;
            }
        }
        i++;
    }
    return Result;
}

and finally

private void Items_SentMailItemAdd(object Item)
{
    //throw new NotImplementedException();
    ; // this event is never fired
}

Answer 1

You can use the Items.ItemAdd event on the Sent Items folder. To check if that is your message, set a custom property on the message that you create and display. You can use MailItem.UserProperties.Add, but that can force the message to be sent in the TNEF format. To prevent that from happening, you can use MailItem.PropertyAccessro.SetProperty to set a named MAPI property without using the UserProperties collection. You can set a test user property and look at its DASL name (to be used by SetProperty) with OutlookSpy (I am its author - select the message, click IMessage button, select your custom property, see the DASL edit box).