Why does the MessageStats database have a large amount of disk space allocated for free space? Should we manually shrink the database? Should we schedule (or not) to shrink regularly? Having 50% of the database added for free space seems like is a lot of usage in our environment, is there any way to determine how much space MessageStats needs and if it is operating normally considering the numbers?
MessageStats does not actually grow the database itself; it is SQL that performs that action. The size is based on the growth % defined on the database properties. It is quite possible that your database is inflated with blank space because of data deletion. You may either manually shrink the database, or schedule a weekly database shrinkage. This however may have an insignificant affect on performance.