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. mxORB is packed with all of the features you will need to eliminate spam. The amazing low price coupled with a success rate of over 98% gives it an unassailable position in today's marketplace.
Mail Storage Guard is an extension for Microsoft Exchange 2000/2003 and IIS SMTP servers, designed to protect your mail server from spam, prevents mail relaying, mail bomb and NDR attacks. Support extended blacklists with wildcards; public DNS blacklists (ORDB, SPEWS, SPAMCOP and others); can reject all "misaddressed" mail (recipient not listed in Active Directory) at SMTP level or point it towards your postmaster; as well as many other features.