NewMail Event
Occurs when one or more new e-mail messages are received in the Inbox.

The NewMail event is useful for scenarios in which you want to be notified when a new e-mail message arrives.
If you want to process items that arrive in the Inbox, consider using the ItemAdd event on the collection of items in the Inbox.
The ItemAdd event passes a reference to each item that is added to a folder.

This Microsoft Visual Basic/Visual Basic for Applications (VBA) example displays the Inbox folder when a new e-mail message arrives. The sample code must be placed in a class module, and the Initialize_handler routine must be called before the event procedure can be called by Microsoft Outlook.

Public WithEvents myOlApp As Outlook.Application 

Sub Initialize_handler() 
    Set myOlApp = CreateObject("Outlook.Application") 
End Sub 

Private Sub myOlApp_NewMail() 
    Dim myExplorers As Outlook.Explorers 
    Dim myFolder As Outlook.MAPIFolder 
    Dim x As Integer 
    Set myExplorers = myOlApp.Explorers 
    Set myFolder = myOlApp.GetNamespace("MAPI").GetDefaultFolder(olFolderInbox) 
    If myExplorers.Count <> 0 Then 
        For x = 1 To myExplorers.Count 
            On Error GoTo skipif 
            If myExplorers.Item(x).CurrentFolder.Name = "Inbox" Then 
                myExplorers.Item(x).Display 
                myExplorers.Item(x).Activate 
                Exit Sub 
            End If 
skipif: 
        Next x 
     End If 
     On Error GoTo 0 
     myFolder.Display 
End Sub