You can download Active roles Quest Management shell from the below mentioned link.

http://www.quest.com/powershell/activeroles-server.aspx

Commands to check if mailbox is active or disabled

Get-QADUser <username> -enabled              

Will get the result if acount in active

Get-QADUser <username> -disabled                

Will get result if account is disabled

Get-QADUser  -Enabled       

Will get  all the enabled in the Active Directory

Get-QADUser  -Disabled      

Will get all the disabled users in the Active Directory

get-content “C:\users.txt” | Get-QADUser -enabled | select Email 

Will get list of all active users email address from the given input users