Option Explicit
Private WithEvents Items As Outlook.Items

Private Sub Application_Startup()
Dim olApp As Outlook.Application
    Set olApp = Outlook.Application
    Set Items = GetNS(olApp).GetDefaultFolder(olFolderInbox).folders("Maria Alencar").Items
End Sub

Private Sub Items_ItemAdd(ByVal item As Object)
    On Error GoTo ErrorHandler
    Beep
    MsgBox "There's a new item in Maria's folder."
ProgramExit:
    Exit Sub
ErrorHandler:
    Beep
    MsgBox Err.Number & " - " & Err.Description
    Resume ProgramExit
End Sub

Private Function GetNS(ByRef app As Outlook.Application) As Outlook.NameSpace
    Set GetNS = app.GetNamespace("MAPI")
End Function