Produced another tool, nothing fancy, shows how many files are in each of the ConfigMgr inboxes in an easy to see way. Beyond listing the file counts it allows you to turn off display of empty inboxes.
Requirements: ConfigMgr 2003, 2007, 2012, .NET 4.5 on the machine running the tool.
I’ve tried using it remotely and locally, for remote connections you can choose to use the SMS_<SITECODE> share or the administrative shares (C$\D$…) to establish the connection dependent on permissions to do either. Was quick and easy to produce, hope it helps somehow.
You can download it here from SourceForge.