This example shows how to generate various header lines for the e-mail message that MailSerf generates. Note that some are hidden, meaning that the user of the form cannot change them, and some are text, meaning that they can or should be changed.
The following HTML form includes user-definable To: and Subject: fields, but the From: field is hidden....
<form action="/cgi-bin/mailserf" method="POST">
<input type="hidden" name="hdr:from" value="nobody@devnull.org">
<input type="text" name="hdr:to"> To<br>
<input type="text" name="hdr:subject"> Subject<p>
<input type="text" name="comments" size="50"> Comments<p>
<input type="submit" value="send form">
<input type="reset">
</form>