Script Download: GetMailboxUsageReport.zip http://gallery.technet.microsoft.com/scriptcenter/Get-Mailbox-Usage-Report-72a72976
This script creates mailbox usage report in Microsoft Exchange 2010. It will use IssueWarningQuota and TotalItemSize to calculate the usage rate.
In a real world, IT Administrators may want to know the usage rate of specific mailboxes. They can use Exchange Management Shell to get total item size and issue warning quota for mailboxes very easily. But issue warning quota could be set for all of the mailboxes in a database or on a per-mailbox basis. IT administrators need a script to help them to decide which quota is applied. Then, they want to use correct issue warning quota to calculate the mailbox usage.
You can find more All-In-One Script Framework script samples at http://aka.ms/onescriptingallery
Good information shared, this article explanation that how to create exchange mailbox size reports. I tried this exchange mailbox reporting tool from
http://www.lepide.com/exchange-reporter/ which helps to create mailbox size report and keep tracks of all user mailbox and its traffic. This tool provides comprehensive email flow reports based on different
criteria including users, email subject, receivers, senders, date wise, size wise etc.