I have this code to send e-mail.
First i copy the sheet TEMPLATE as workbook from the active workbook with: Worksheets("TEMPLATE").Copy
(i think this is the first operation to attach the sheet into email, or not?)
and when the code go in: .Attachments.Add ActiveWorkbook have error?????

Code:
Sub INVIO_STATISTICA()

    Dim OutApp As Object
    Dim OutMail As Object
    Dim TEMPNAME As String
    Dim DATA As Date, WS_T As Worksheet
    Dim DRIVER As String, DATA_SALVA As String
    Dim GIORNO As String, MESE As String, ANNO As String

    On Error GoTo errore

    Application.ScreenUpdating = False

    Set OutApp = CreateObject("Outlook.Application")
    OutApp.Session.Logon
    Set OutMail = OutApp.CreateItem(0)

    DATA = Format(CDate((Now)), "DD/MM/YYYY")
    GIORNO = Left(DATA, 2)
    MESE = Mid(DATA, 4, 2)
    ANNO = Right(DATA, 4)
    DATA_SALVA = GIORNO & "-" & MESE & "-" & ANNO

    Worksheets("TEMPLATE").Copy
  
    With OutMail

        .To = "AAAAA"
        .CC = ""
        .BCC = ""
        .Subject = "DDDDDDDD"
          .HTMLBody = STRBODYTEXT_4
        '.Body = ""
        .Attachments.Add ActiveWorkbook
        .Display
        '.Send

    End With

    Set OutMail = Nothing
    Set OutApp = Nothing    '

    Application.ScreenUpdating = True

    Exit Sub

errore:
    MsgBox "Errore Numero: " & CStr(Err.Number) & vbCrLf & _
           "Descrizione: " & Err.Description & vbCrLf & _
           "Sorgente dell'Errore: " & Err.Source

    Err.Clear

End Sub