After you disable mailbox, you can view all the disconnected mailbox using Exchange Management Shell (EMS).
Get-MailboxStatistics -Server <server> | where { $_.DisconnectDate -ne $null } | select DisplayName,DisconnectDate
Ok, here the story. I’ve got 1 box SCCM Server, include PXE Service Point (PSP), WDS installed in it too.
First of all the DHCP is using a network device, because limitation of the network device operating system then I decided to install DHCP roles at the SCCM server.
But after the DHCP is up, the Admin guy decided that the DHCP server have to move to Domain Controller. Of course I remove DHCP roles at SCCM server.
Then something bad happen! I can’t deploy OSD again 
no error issue at SCCM logs, then I go to event viewer Windows Deployment Service, bingo! this error came up:
An error occurred while trying to create the UDP endpoint for WDSTFTP provider on interface 10.1.1.6:69. This can happen if the network interface was disabled or changed, or some other application is already using the port. The provider will not be able to receive requests on this interface.
Error Information: 0x2740
I really think hard what’s really happen with the network interface, what the hell happen anyway?! 
After some tracing down the event viewer, the error appear after I restart SCCM server, after I remove the DHCP roles!
So I’m guessing the DHCP roles not remove cleanly. The binding to my network interface still there. So the solution is deleting registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\<guid>
Just delete the guid that have DHCP entry in it, crazy huh? But it works, error gone 
So many maintenance task running at SCCM server, to figure it out, you need a query to your SCCM Database, here you go:
select *,
floor(DATEDIFF(ss,laststarttime,lastcompletiontime)/3600) as Hours,
floor(DATEDIFF(ss,laststarttime,lastcompletiontime)/60)- floor(DATEDIFF(ss,laststarttime,lastcompletiontime)/3600)*60 as Minutes,
floor(DATEDIFF(ss,laststarttime,lastcompletiontime))- floor(DATEDIFF(ss,laststarttime,lastcompletiontime)/60)*60 as TotalSeconds
from SQLTaskStatus
the result just like this, neat isn’t it 
taken the source from: http://anoopmannur.wordpress.com/2010/12/06/reporting-of-maintenance-tasks-status-of-sccm-primary-server/