private void buttonSend_Click(object sender, RoutedEventArgs e) { try { if (mailMessage.Busy == false) { string t = this.textBoxMailTo.Text; string lastFour = t.Substring(t.Length - 1, 1); if (lastFour == ";") { string s = textBoxMailTo.Text.Substring(0, textBoxMailTo.Text.Length - 1); textBoxMailTo.Text = s; SendMail(); } else { SendMail(); } } else { mailMessage.Abort(); listBoxAttachments.Items.Clear(); } } catch (Exception ex) { MessageBox.Show(ex.Message, "Error", MessageBoxButton.OK); } }