Re-routing mail traffic through a LiveOffice network, the service provides Microsoft Exchange Server functionality (including archiving, journaling and search) in the event of the failure of your primary mail server.
Rolled out as part of the company's latest update of its Mail Archive product, purchase of Mail Archive is not required for use of the free continuity service.
According to LiveOffice the service can be deployed in a matter of days (hence their recommendation that that you sign up before disaster strikes.)
Should your primary server go down, a toll-free call (assuming you have phone service) to LiveOffice shifts your mail to their portion of the Cloud.
Seven days' rolling archiving is included in the free service.
This one should be worth a look, particularly in light of the disruptions we've seen -- and many experienced firsthand -- as a result of recent hurricanes.
And here's a bMighty look at e-mail archiving.