If you are looking from a simple to use and dependable application that will enable you to filter and block spams then a great solution is offered by the handy SpamSieve software.
Although email service providers use various filtering techniques, spam still passes through and, worse, it ends up blocking important non spam emails. The SpamSieve utility uses Bayesian spam filtering that provides a more reliable and accurate filtering solution, which is designed to adapt to your email characteristics; thus effectively blocking junk and preventing good messages going in the spam folder.
SpamSieve can be easily configured directly from within your mail client. This helpful piece of software is highly configurable by allowing you to define how to interact with the message sorting rules. You will be able to create a Blocklist that is designed to block spam by content, title, address and many more characteristics that can be easily modified. Moreover, SpamSieve will even search inside the email attachments for spammy content thus blocking almost all undesired content.
To sum it all up, if you need a user friendly, highly configurable and effective spam blocking application then you will find the SpamSieve software as a great solution.