title: C# change e-mail 'from' address to a user-provided one
body: <p>We have an app that allows users to send e-mails from our system.  It allows the user to specify their e-mail address, and gives them several standard templates to use as a starting point for their e-mail.</p>
  
  <p>When we send the e-mails, we use the address they provided as the 'reply-to', but the 'from' address of the e-mail (naturally) looks like our system (from 'submit@ourserver.com').</p>
  
  <p>Is there a way to change this without getting tangled up in spam filters or automatic blocking? We'd prefer not to confuse the recipient as to who actually composed the e-mail they've received.</p>