Vanguard

With Vanguard you get complete protection for your mail server. Vanguard has a number of advanced features that allow tight integration into systems comprising any combination of messaging servers including their infrastructure requirements such as Active Directory.
Dual anti virus scanning engines provide both traditional signature based virus protection and advanced Zero Hour protection. The use of such complementary technologies provides a high level of protection to end users. Outbound scanning further protects your corporate reputation and ensures infected messages are never transmitted in either direction.
Vanguard delivers large quantities of e-mail messages quickly and efficiently. It does this by using sophisticated queuing algorithms to re-use connections, and by using Enhanced SMTP and other features. This means you do not need a top range PC to run Vanguard.
Vanguard reduces the bandwidth needed to deliver and accept messages to and from the Internet. You can limit the bandwidth used for outgoing mail to avoid saturating a low bandwidth link.Limitations in the unregistered version14 days trial
It will stop allowing you to read your email or send mail after 3 days