It is still a beta version! This is a simple service - MX Backup.
If you run your own mail server, our backup mail service is essential to make sure you receive all of your important email. If your mail server is down or unavailable, Backup MX will accept the messages and then deliver them once your mail server is restored.Getting started
MX EMail Server Backup - perfect solution for small business (Microsoft™ Exchange Servers and other email solution)
While you're down, we'll get it all -- no matter how big.
We filter our mail against our DNSBL (DNS black hole list), filtering and discarding any email with bad intentions.