Mixed reviews on the Google Apps marketplace for backupify: https://www.google.com/enterprise/marketplace/viewReviews?pr... -- 27 users take 21 days to backup? Might well be the Google Apps infrastructure that's not up to the task. Looking at my company's Google apps domain, we probably have several million threads and are close to a terabyte of data. I imagine backing that up via IMAP could take a while.