**** UPDATE 04/03/2019 ****
Thanks all for the comments over the years on this script. It was something that I put together while working as a consultant for a partner and at the time was more or less a demonstration of the distribution of mailboxes across a wide number of databases and servers. I have since taken a role at Microsoft and much has changed in the service including a number of new datacenters and the offering of multi-geo capabilities. I have removed this script based on the comments by Brian Day regarding the accuracy of the attribute being used; unfortunately I have no access to the original blog post as it is on my former's employers site.
When you move your mailboxes to the cloud, there are some details that you lose a little bit of insight into. While an acceptable answer to "where are my mailboxes" might be "the cloud", I was curious as to how distributed it is.
Additional information on the usage of this script can found at the following blog post: