WINNER: MX Logic Email Defense Service
With a simple, yet comprehensive management interface, excellent accuracy and distinctive features, the MX Logic Email Defense Service impressed us. It uses various, aggregated techniques to fight spam. It looks at different parts of the message, including the Sender ID record and contents, and applies a slew of analysis against it.
Whitelists, blacklists and multilanguage filtering are just a few of the tools in its arsenal. In addition, by using a statistical Bayesian algorithm, MX Logic estimates the likelihood that a particular e-mail is spam by comparing how often its contents have previously appeared in spam e-mails. Confirmed spam is blocked, while legitimate messages are delivered. E-mails that may or may not be spam are stored in user-specific quarantines accessible online.
Through the MX Control Console, a Web-based management interface, attachment and HTML filters can be selected. By default, MX Logic rejects messages flagged as high spam and quarantines medium messages. Since the service depends on the DNS entry having an updated MX record (redirected to MX Logic's servers), it took a few days before we were able to see results. Once everything was in place, though, our test account had only one message every few days in quarantine that was fit to release and whitelist, and only one spam message that squeaked through each day.
MX Logic also offers a Message Continuity feature, where mail is queued if the mail server is down. Users can log in and read and reply to their messages even during an outage. Some solution providers use this feature as part of a planned migration when moving one mail server to another.