In today’s fast paced world, the importance of having an e-mail service needs no further explanation. We all use it on a daily basis, relying on it to keep in touch with the surrounding world. However, when the throughput of information becomes so great that a simple system cannot keep up with it, new methods must be deployed to cope with the growing requirements of networks and their users. Clusters fill up the gap between the need for faster, more powerful systems, and the safety, reliability and easy management of the already existing networks.