if (db.Connection.State != System.Data.ConnectionState.Open)
                db.Connection.Open();

            db.Transaction = db.Connection.BeginTransaction();

            try
            {
                db.Messages.InsertOnSubmit(newMessage);
                db.SubmitChanges(); //Salvo i dati del messaggio e recupero l'ID che mi servirà per i dati successivi
                db.Attachments.Insert(newMessage.MessageId, attachments);
                db.DistributionLists.Insert(newMessage.MessageId, newMessage.ApplicationId, distributionLists);
                db.SubmitChanges(); //Salvo i dati delle 2 insert precedenti
                db.Transaction.Commit();
                db.Connection.Close();
            }
            catch (Exception)
            {
                db.Transaction.Rollback();
                if (db.Connection.State == System.Data.ConnectionState.Open)
                    db.Connection.Close();
                throw;
            }