ASP Email Submit Button

try
            {
                MailMessage mailMessage = new MailMessage();  
                //MailMessage used to Represent Email Message             
                
                mailMessage.To.Add("receiver1@gmail.com");    
                mailMessage.CC.Add("receiver2@gmail.com");
                mailMessage.Bcc.Add("receiver3@gmail.com");
                //Specify receiver email-ID in CC or Bcc                   

                mailMessage.Subject = "This is Mail Subject";
                //Specify Subject of Mail Message

                mailMessage.Body = "This is Mail Body";
                //Specify Body of Mail Message

                //Specify Credential like sender email-id and password   
                System.Net.NetworkCredential credential = new System.Net.NetworkCredential();
                credential.UserName = "sender@gmail.com";
                credential.Password = "Password";

                SmtpClient smtpClient = new SmtpClient("smtp.gmail.com", 587);
                //SmtpClient allow application to send mail using smtp
                //You need to specify host and post Please refer below link to find most frequently used SMTP like google, Yahoo, outlook                   

                smtpClient.Credentials = credential;
                //Specify Credential to SmtpClient object so using this credential Application can send Mail
  
                smtpClient.EnableSsl = true;
                //You can enable SSL to encrypt connection

                smtpClient.Send(mailMessage);
                //Send Message that represent in MailMessage object 
            }
            catch (Exception ex)
            {
                Response.Write("Could not send the e-mail - error: " + ex.Message);
            }