Change "Item.To" value in outlook when sending a message using VBA

I'm trying to change the email address in Send To field in Outlook when the user press send button. for example , if the current Item.To value = 'aaa@example.com' it becomes 'bbb@example.com'.

I can change the subject , but failed with Item.To ( is it security issue ? ) :

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)

   If Item.Class <> olMail Then Exit Sub

   Item.To = "bbb@example.com"  ' Nope , It doe开发者_运维技巧s not work
   Item.Subject = "New Subject" ' It works

End Sub

Thanks

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The MailItem.To property is used only for display names. You probably want to use the Recipients collection as in this slightly modified example from Outlook's Help on the MailItem.Recipients property:

Sub CreateStatusReportToBoss()

 Dim myItem As Outlook.MailItem
 Dim myRecipient As Outlook.Recipient

 Set myItem = Application.CreateItem(olMailItem)
 Set myRecipient = myItem.Recipients.Add("bbb@example.com")
 myItem.Subject = "New Subject"
 myItem.Display

End Sub

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I'm the question owner. I chose @joeschwa answer but also I want to display my code that cancel the current message and create new one ( you can change the recipients , message contents and anything else ) :

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)

   If Item.Class <> olMail Then Exit Sub
   Dim newEm As String

   Dim Rec As Recipient
        Dim myItem As Outlook.MailItem
        Dim myRecipient As Outlook.Recipient
        Set myItem = Application.CreateItem(olMailItem)
        myItem.Body = Item.Body
        myItem.HTMLBody = Item.HTMLBody
        myItem.Subject = Item.Subject & " RASEEL PLUGIN "
        Cancel = True


   For Each Rec In Item.Recipients
    If InStr(1, Rec.AddressEntry, "@example.com", vbTextCompare) Then
        newEm = "example@example.net"
    Else
        newEm = Rec.AddressEntry
   End If

    Set myRecipient = myItem.Recipients.Add(newEm)
    myRecipient.Type = Rec.Type

   Next

   myItem.Send

End Sub

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It works for me. However, when changing recipient, it is also necessary first to delete the previous recipient. For example,

x = .recipients.count if x = 1 then .recipients(1).delete
.recipients.add "abc@dfg.com"