The largest source of spam for me is the VAST unwashed masses using email. Those people blissfully unaware that email predates the interweb. I no longer have the patience to re-educate each on BCC and email netiquette so I have finally accepted the necessity of proximate circles of trust. The more trusted the contact the better email contact information provided. My peripheral email address uses self destructing images, self destructing URLs, and disposable email aliases to send content that is likely to tempt the ignorant into mashing her FWD button.
drop : media :: kicknotes : text :: vipurl : url
When their respective recipients receive the email with URLs to content that is no longer available the feedback loop discourages them from forwarding my email.
^ I have been emailing various services for more than a year pressing for self expiring options. Seemingly there are many new fruits of this effort. :-}
This is far more convenient that using a cPanel webhost for DIY expiration. (ftp + mod_rewrite + cron + pixie dust)