One common Exchange administrative task is to find the total size of mailboxes in the environment. This can be useful to find the biggest mailboxes or ones that are (nearly) empty as targets for removal due to inactivity. However, mailbox sizes are only available via PowerShell, and depending on where you run the Get-MailboxStatistics command, the options for sorting the output may require additional work.

Read my full article over at the 4Sysops Blog: