title: Complete requirements for HTML E-mail Contact Forms
body: <p>Everywhere I've looked, from youtube, to w3schools, to the php manual (just to mention a few), none of them provided in-depth details about the requirements of successfully sending a secure email from a simple contact form...</p>
  
  <p>Construction of the form and client/server validation aside, <b>what exactly do I need to know to securely send the results via email using the php mail() function?</b> (since it's not a heavy task for which Perl works better according to the PHP manual).</p>
  
  <p>What is SMTP?, what is authentication and in what case do I need it?, what are headers?, what is x-mailer?, how exactly do I implement it all together, and what have I missed?</p>