This post is not specific for Exchange but I know several companies that are struggling to keep it up with old PSTs files that are should stay for legal purposes for years to come. This post below can help to address that issue in a simple way using Azure.
Cloud adoption in healthcare has a large footprint and is continuing to grow quickly. In a recent survey conducted by HIMSS Analytics, 80 percent of the 150 healthcare organizations across the U.S. who responded reported that they currently use cloud services to help reduce maintenance costs, speed deployment of new applications and address the lack of internal resources needed to support technology. The survey further indicated that those healthcare organizations experienced in using cloud, plan to expand and grow their cloud services footprint.
Read more at source: http://blogs.technet.com/b/work/archive/2014/08/07/microsoft-azure-helps-lower-the-cost-and-complexity-of-medical-image-archiving.aspx