title: How to send email via exchange server without using smtp?
body: <p>I'm trying to send an email from c# code via our company's exchange server. </p>
  
  <pre><code>System.Net.Mail.SmtpClient client = new System.Net.Mail.SmtpClient("exchangebox1.mycompany.com");
  System.Net.Mail.MailMessage msg = new System.Net.Mail.MailMessage("Me@myCompany.com",
                  "Them@mycompany.com",
                  "title here",
                  "body here");
              client.Send(msg);
  </code></pre>
  
  <p>When I run this I get SmptException saying "Service not available, closing transmission channel. The server response was 4.3.2 Service not available, closing transmission channel".</p>
  
  <p>I'm interpreting this to mean SMTP is not enabled on our exchange box and that I need to use native Exchange Server commands to send the mail. Is this right, or should SMTP always work?</p>
  
  <p>Additionally, is it possible the exchange server could have been configured to only allow certain computers/users to send main via SMTP?</p>
  
  <p>How can I send mail via the Exchange Server without using SMTP?</p>
  
  <p>Thanks.</p>