Reducing spam to 20 % of its original value with a SMTP tar pit simulator

Unsolicited commercial email (UCE, spam), scam and phishing emails make up for more than 90% of all emails sent world-wide. Most antispam methods known rely on filtering emails. Meanwhile, browsers also check URLs against blacklists to avoid fraud. However, all those methods are reactive, ergo they are only able to deal with known attack patterns. Some methods are computing intensive, thus require very powerful CPUs and lots of memory. They also require regular updates and lots of maintenance. An ideal solution would neither consume computing power nor require maintenance.