The next step in the spam control war: greylisting

Wednesday, 3 March 2004, 12:07 PM EST

This paper proposes a new and currently very effective method of enhancing the abilities of mail systems to limit the amount of spam that they receive and deliver to their users. For the purposes of this paper, we will call this new method "Greylisting". The reason for choosing this name should become obvious as we progress.

Greylisting has been designed from the start to satisfy certain criteria:

- Have minimal impact on users
- Limit spammers ability to circumvent the blocking
- Require minimal maintenance at both the user and administrator level

User-level spam blocking, while somewhat effective has a few key drawbacks that make its use in the continuing spam war undesirable. A few of these are:

- It provides no notice to the senders of legitimate email that is falsely identified as spam.
- It places most of the costs of processing the spam on the receivers side rather than the spammers side.
- It provides no real disincentive to spammers to stop wasting our time and resources.

By Evan Harris at

[ Read more ]

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