When studying the event log over a steaming hot cup of coffee, have you ever seen the following directory event (2914)?

Process w3wp.exe (UNKNOWN) (PID=15780). Deleted throttling policy was referenced.  Id: 'Org: SomeOrg…/Configuration, Id: CN=ThrottlingPolicy-DefaultMailboxPlan\0ADEL:4d73d344-d66f-4eed-85f9-b6c95dcd2a13,CN=Deleted Objects,CN=Configuration,DC=…,DC=com'.

This one does require some action. In the case of this event log, a throttling policy was deleted from Active Directory, but because *someone* did not use Remove-ThrottlingPolicy to do so, the links from the associated mailboxes did not get updated properly. The fix is relatively easy – you just need to reassign the affected mailboxes to a valid throttling policy. Now, I highlighted the “\0ADEL” wording in the event log for a reason. That is a very reliable way to determine whether we are dealing with a deleted object in Active Directory. We can use that to our advantage in the Exchange Management Shell.

[PS] D:\Windows\system32>get-mailbox | ? {$_.ThrottlingPolicy -ilike "*`nDEL*"} | fl Name, ThrottlingPolicy

Name             : JohnDoe
ThrottlingPolicy : SomeDomain/Configuration/Deleted Objects/SomePolicy
                   DEL:3fb98144-b317-413b-9a19-78003fd5a633

The key is in the “*`nDEL*” string.  The value “`n” is the Exchange Management Shell’s way of escaping the new-line sequence.

Now that we have discovered the mailbox that is having the issue, we can assign that mailbox to another policy. In my case, I just want JohnDoe to use the default policy, so I will just null out the ThrottlingPolicy parameter.

get-mailbox | ? {$_.ThrottlingPolicy -ilike "*`nDEL*"} | set-Mailbox –ThrottlingPolicy $null

Even with this problem present, the throttling policy framework was behaving properly and “falling back” to the default throttling policy governing John Doe. However, it is a good idea to clean up these issues in the directory if you encounter them and make your throttling policy association links explicit rather than relying on the fallback logic to do the “right thing”.

David Sterling
Exchange Web Services
Inside Microsoft Exchange Server 2007 Web Services