Spamihilator - The free Anti-Spam-Filter Spamihilator removes more than 98% of spam mails before they even get into your inbox.
Cryoserver - Cryoserver is an all-in-one email archiving solution that empowers you to preserve your email in a tamper-evident archive, making you transform your data into a useful archive for everyday use.
Mailwasher - Over 8 million people use MailWasher as their spam filter
Hornetsecurity Email Archiving - Hornetsecurity Email Archiving is one of the advanced software that offers long-term, unchangeable, and secure storage of important company information, data, and flies.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
MailStore - MailStore Home - A 100% free single-private-user desktop solution