protected void btnSubmit_Click(object sender, EventArgs e) { string email = txtEmail.Text; string password = txtPassword.Text; int abc = ddlEmailProvider.SelectedIndex; if (Session["tempEmail"] != null) { EmailClass emailClass = (EmailClass)Session["tempEmail"]; try { EmailCredential emailCredential = new EmailCredential(new NetworkCredential(email, password), EmailClass.getStmpClient(ddlEmailProvider.SelectedValue)); emailClass.sendEmail(emailCredential); EmailClass.generateCredential(email, password, EmailClass.getStmpClient(ddlEmailProvider.SelectedValue)); string url = Request.QueryString["ReturnUrl"]; Response.Write(" <script language = 'javascript'> window.alert('Email has been sent. Redirecting previous page.'); window.location = '" + url + "';</script>"); } catch (SmtpFailedRecipientsException stmpRecipientsException) { lblError.Text = "Email failed to send to " + stmpRecipientsException.FailedRecipient; } catch (SmtpException smtpException) { lblError.Text = "The email or password might typed wrong or " + smtpException.Message; } } else { lblError.Text = "There is no email to be send, credential is not created."; } }