string[] varArr = new string[] { "This", "message", "will", "be", "send", "correctly" };
            StringBuilder sb = new StringBuilder();
            DateTime startingTime = new DateTime(2007, 12, 1);
            DateTime dtfinal = new DateTime(2007, 12, 10);
            foreach (string var in varArr)
            {
                sb.Append(var + Environment.NewLine);
            }
            string str = string.Format("Starting time: {0} \nFinishing time: {1} \nInformation: {2}",
                startingTime.ToString(), dtfinal.ToString(), sb.ToString());

            richTextBox2.Text = str;