title: Unable to add reply to in mail header C#
body: <p>I am developing Windows Form Application, Dot net Framework 4.  for sending SMTP emails.</p>
  
  <p>I am using following code to send email. </p>
  
  <pre><code>MailMessage mail = new MailMessage("\"Company Name\" &lt;info@company.com&gt;", textBox_Email_to.Text);
  
  SmtpClient client = new SmtpClient();
  client.DeliveryMethod = SmtpDeliveryMethod.Network;
  client.UseDefaultCredentials = false;
  client.Host = "host name";
  
  mail.Subject = "test email";
  mail.Body = file; // file contains some text
  mail.Headers.Add("reply-to", "service@company.de");
  mail.IsBodyHtml = true;
  client.Send(mail);
  </code></pre>
  
  <p>The only problem is <code>mail.Headers.Add("reply-to", "service@company.de");</code> is not working.</p>
  
  <p>I also tried to use <code>mail.ReplyTo = new MailAddress("service@company.de");</code></p>
  
  <p>But still its not working. While using <code>mail.ReplyTo</code> I am getting this warning:</p>
  
  <p>'System.Net.Mail.MailMessage.ReplyTo' is obsolete: '"ReplyTo is obsoleted for this type.  Please use ReplyToList instead which can accept multiple addresses. </p>