Copy method in ItemAdd generates Runtime Error - vba

Question

When I run this code I get the error:
Run-Time error '-2147221233 (8004010f)':
The attempted operation failed. An object could not be found.
Everything is working despite the error.
The error disappears if I change the line
'MsgBox "Awesome"
to
MsgBox "Awesome"
A few tests showed that the error does occur if item.Sendername is used with the copy part. If I do just move the mail it works perfectly.
If I try to use the code separately it works without errors.
Private WithEvents snItems As Items
Private Sub Application_Startup()
Set snItems = Session.GetDefaultFolder(olFolderSentMail).Items
End Sub
Private Sub snItems_ItemAdd(ByVal item As Object)
Dim CopiedItem As MailItem
Dim ShareInbox As Outlook.MAPIFolder
Dim MapiNameSpace As Outlook.NameSpace
If TypeName(item) = "MailItem" Then
Set MapiNameSpace = Application.GetNamespace("MAPI")
Set ShareInbox = MapiNameSpace.Folders("Support").Folders("Send Mails")
If item.SenderName = "Support" Then
Set CopiedItem = item.Copy
CopiedItem.UnRead = True
CopiedItem.Move ShareInbox
End If
End If
'MsgBox "Awesome"
ExitRoutine:
Set ShareInbox = Nothing
Set CopiedItem = Nothing
Set MapiNameSpace = Nothing
End Sub
There is no error if not copied.
It is ok with the following Code
Set MapiNameSpace = Application.GetNamespace("MAPI")
Set ShareInbox = MapiNameSpace.Folders("Support").Folders("Gesendete Elemente")
If item.SenderName = "Support" Then
item.Move ShareInbox
End If

Answer 1

Copying the item adds an item to the Sent Items folder, triggering the ItemAdd code.
Disable the ItemAdd event temporarily.
Private Sub snItems_ItemAdd(ByVal item As Object)
Dim CopiedItem As MailItem
Dim ShareInbox As Outlook.MAPIFolder
Dim MapiNameSpace As Outlook.NameSpace
If TypeName(item) = "MailItem" Then
Set MapiNameSpace = Application.GetNamespace("MAPI")
Set ShareInbox = MapiNameSpace.Folders("Support").Folders("Send Mails")
If item.SenderName = "Support" Then
' Turn off event handling
Set snItems = Nothing
Set CopiedItem = item.Copy
CopiedItem.UnRead = True
CopiedItem.Move ShareInbox
' Turn on event handling
Set snItems = Session.GetDefaultFolder(olFolderSentMail).Items
End If
End If
ExitRoutine:
Set ShareInbox = Nothing
Set CopiedItem = Nothing
Set MapiNameSpace = Nothing
End Sub