Batch backup of Google Apps accounts

Hello!

I was wondering if there is any way to batch backup all accounts pertaining to some domain hosted on Google Apps service.

For example, I can backup separately tim@crono.com, jim@crono.com and etc. And how about backing up whole @crono.com domain accounts?

Thus, it would be convenient for a company to assing backup job to a system administrator and all users' mail will be secured.

Thank you in advance.