MailWasher Free blocks spam with any e-mail client, because of the unique way it works. Rather than blocking spam after you download it, it checks mail on your server before you run your email client. You then examine what you've got waiting, tell the program to kill what you consider spam, and let the rest through.
The program lets you create blacklists and filters, so that it will automatically detect and kill spam, without you having to take manual action. It also does some basic anti-virus detection as well. The program will work with just about any type of mail server, including POP3, IMAP, and several Web-based email sites. Consider it a first line of defense rather than a comprehensive anti-spam program, because it can be difficult for you to recognize spam on your own. A $40 for-pay version of the program, MailWasher Pro, includes extra features, such as a constantly updated list of known spam senders, and the ability to learn from you about what you consider spam.