title: How to implement Sender ID when sending mails through C#?
body: <p>I just heard Joel &amp; Jeff talk about Sender ID in their podcast number 83, and it occurred to me that's just what I need for a site I'm working on.</p>
  
  <p>Approximately 90% of all e-mails sent from the server is bounced or similar, likely because the server isn't "validated".</p>
  
  <p>I have a SPF record in place for the server, but that's also pretty much it.</p>
  
  <p>So since StackOverflow have solved these issues, I guess Sender ID must be the way to go.</p>
  
  <p>As far as I can tell from wikipedia, it requires you to modify the mail header when sending mails - how would I go about doing this from C# ?</p>
  
  <p>Also what would I need to setup DNS wise, etc. to make this work ?</p>
  
  <p>Or am I onto a completely wrong track here ?</p>
  
  <p>Edit: I'm using the standard SmtpClient class in C# for sending mails, and I do include both a plaintext and a HTML version of the mailbody.</p>