How can I prevent spam while letting users email content to their friends?
<p>I'm working on an app (in PHP &amp; JavaScript) that lets users generate content (short stories), and I want to add in a "email this to your friend" button.</p>

<p>I'm worried, though, that this could be used to send spam.</p>

<p>What are some things I could do to prevent that from happening? I am thinking:</p>

<p>1) The user must confirm their own personal email address before I send it
2) I have a hidden field somewhere that bots would fill in</p>

<p>What else should I do?</p>

<p>Cheers</p>
