An easy powershell comment can help to get more info about a messagequeue.
This get more info on all the queue's you have defined:
# Get all message queues
The next command gives youa table overview of all queue's and their item count:
# Get all the private message queues.
# Display only the QueueName and MessageCount for each queue.
Get-MsmqQueue -QueueType Private | Format-Table -Property QueueName,MessageCount;
You could off also take a look in the queue browser: