Table of contents

1. Introduction
   1. The Social Problem
2. What is DNS
3. What is PKI
4. PKI and DNS
5. How can you fight SPAM using PKI
   1. Whitelists and blacklists
6. Different standards
   1. Public Key Association
      • What is GNU Privacy Guard
   2. Sender Policy Framework
   3. DomainKeys
7. Conclusion

Introduction

Spam is an increasing problem. A multitude of working hours are wasted by employees sorting through spam messages and many are starting to get fed up by the ever-increasing amount. The spam versus ham distribution on one of the low-traffic (500 messages a day) email servers under KF Webs control is as follows:

An average of 58% of the emails received by the server is SPAM-messages.

The Social Problem

As long as it is profitable to send SPAM messages, people will continue doing so. The only way to truly fight SPAM is for it not to be profitable, and to do so one have to educate users not to click spam links, for their own good with regards to phishing as well to reduce the overall amount of SPAM.

Until that will happen, however you have to take measures to reduce the problem for yourself. Anti-spam solutions such as Spamassassin and dspam are helpful in reducing the problem, but still more has to be done. There is where this article hopefully helps understanding some available and coming technologies.