1)   602LAN SUITE 6.0.08.0714
Secure messaging solution with web collaboration containing SMTP/IMAP/POP3/LDAP services along with integrated anti-virus and advanced anti-spam protection. Native Outlook support provides synchronization of mail, contacts, tasks, and calendar items.
groupware, collaboration, messaging, email, e-mail, mail, fax, task, calendar, contacts,

 2)   SpamSquash 2.0.1
SpamSquash is a spam filter that uses two methods for filtering, a Bayesian filter and DNS black lists. It's used with a third party pop3 email client, such as MS Outlook and Pegasus Mail. It also includes white and black lists. Gets over 99%.
spam filter, email filter, bayesian filter, pop3 filter, SpamSquash, email, dnsbl, outlook, pegasus, spam,

 3)   mxORB 2.2.3
mxORB is a server-side spam filter that consistently blocks over 98% of unsolicited commercial email (also known as spam) at a fraction of the cost of other filtering solutions.
exchange 2000 spam filter, exchange 2003 spam filter, exchange spam filter, exchange, iis, smtp, uce, unsolicited commercial email, spam, filter,

 4)   ORF Enterprise Edition 2.1
ORF Enterprise Edition is an enterprise-level anti-spam solution that helps you to block spam before it reaches your network. ORF uses a combination of anti-spam technologies to stop the spam on SMTP protocol level.
exchange, spam filter, dnsbl, open relay, rbl, email filter, anti-spam,

 5)   Anti-Spam Blacklist Thing 1.1
Anti-Spam Blacklist Thing lets you check to see if a given IP address or hostname is on one of up to 20 different anti-spam blacklists. Anti-Spam Blacklist Thing is provided by SpamButcher completely free of charge.
dnsbl, blacklist, black list, blocklist, block list, dns, utility, blackhole, spam filter, anti-spam,