MessageOne's whole premise is that it's easier and possibly cheaper to provide e-mail filtering, continuity, and archiving from the Net than for organizations to use software and appliances and roll their own solutions. For many organizations, especially those with many distributed servers, it may be. Let's take a look at how each of their services looks against the popular alternatives.Starting with filtering, MessageOne uses technology from ProofPoint to filter viruses and spam out of the incoming mail stream. It has the kind of features most users want, including user-by-user whitelists, blacklists, and quarantine. At around $1/user/month, it's more expensive than comparable service from Postini/Google but in line with the TCO of an appliance.

For continuity, it snatches data from Exchange using event sinks, sends it to their platform in the data center, and populates a Linux mail server with the data. You can specify how long to keep items in each mailbox, so execs can have 90 days of messages and most folks just a week to keep the storage costs down. You can fail-over a user, group, or whole server when testing or troubleshooting.

If I used a replication and fail-over solution like NeverFail or Sonasoft the software would set me back $6,000 to $10,000 and I'd need to set up, monitor, patch, and eventually replace a server at a disaster recovery site where I'd also have to pay to have them house the server. If I have a bunch of branch offices, I'd love to pay $300/month for 100 users at each site than maintain 20 fail-over systems.

Finally, for archiving it just ups the retention period on its mail server, indexes the contents, including the contents of 300+ types of files, and gives you a cross-mailbox search/eDiscovery user interface. It's not quite as cool as a Centera, but at $1/user and storage charges that may add another $1 a user, it's a lot cheaper.

Archiving software like Symantec's Enterprise Vault or Mimosa Systems' NearPoint costs $20 to $50 a user. Add in a server, storage, and backups and $2/user/month may not look bad. On the other hand, you won't stub as much data with MessageOne as you might with an on-site archive since users will notice that retrieving a stubbed attachment over the Internet is slower than from the Exchange server.

Oh, yeah, it's one console for your Exchange Admin to learn, not one each for filtering, fail-over, and archiving.