New Zealand-based Marshal Software, now part of NetIQ, might not be so well known as some vendors in this Group Test, but it has produced an impressive product in its MailMarshal application, a fully-fledged email security solution.
MailMarshal is suitable for any type of organization. For small businesses, it can be used to replace the existing mail server and act as a POP3 server for up to 500 users. Larger organizations can co-locate the product on their SMTP server (although this is another spool-and-forward application, so performance is an issue), or install it on a dedicated machine.