title: System.net.mail attachment gets .xml file extension
body: <p>I have to mail several files to an e-mail address. The files needs to have .tcx file extension. These are in fact xml files (Garmin bicycle logs).</p>
  
  <p>Apparently when the receiver gets the email, the attachement is named xxxxx.tcx.xml. How can I force the mailer not to change the attachment file name?</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Web;
  using System.Web.UI;
  using System.Web.UI.WebControls;
  using System.Net.Mail;
  using System.IO;
  
  namespace stravamailer
  {
      public partial class _Default : System.Web.UI.Page
      {
          protected void Page_Load(object sender, EventArgs e)
          {
              var files = Directory.GetFiles("E:\\JurgenS\\Downloads\\allrides");
  
              for (int i = 0; i &lt; files.Length; i++)
              {
                  MailMessage oMail = new MailMessage();
                  oMail.Body = "";
                  oMail.From = new MailAddress("jurgen@ccccc.be","Jurgen Stillaert");
                  oMail.Subject = "";
                  oMail.To.Add(new MailAddress("jurgen@cccc.be"));
                  Attachment att = new Attachment(files[i]);
                  att.Name = Path.GetFileName(files[i]);
                  oMail.Attachments.Add(att);
  
                  SmtpClient oSmtp = new SmtpClient("uit.telenet.be");
                  oSmtp.Send(oMail);
              }
          }
      }
  }
  </code></pre>