The Mail Dike is a system to stop spam by imposing SMTP restrictions. The main focus is on flexible and efficient greylisting. It consists of two main parts:
In addition a MySQL database is used to store configuration and greylisting data.
The concept of greylisting is described at http://www.greylisting.org and is not covered here.
Since greylisting only controls whether a sender is a maintains a queue, not if the received e-mail is spam or not, it makes sense to white list mail servers that is known to queue. In Mail Dike this is done by automatically white list a sending IP-address when e-mail using a given number of triplets from the same server has passed.
Since greylisting will delay some e-mails, it might be desirable to turn it off at times when users are most dependent of their e-mail. This can typically be during office hours.
Mail Dike uses whitelists for both e-mail addresses of senders and IP-addresses.
White lists and blacklists can be configured globally or per domain or e-mail address.
| info@uninett.no | 2010-04-29 |