Netmail Archive 184.108.40.2069 and higher
Microsoft Exchange 2010, 2013
Not all folders will be archived from mailboxes containing an unusually large number of folders, subfolders, and messages because of the built-in limits of the assigned default EWS throttling policy. Client throttling policies are used to manage the performance of an Exchange organization, and to do this, Exchange tracks resources consumed by each user and enforces connection bandwidth limits, as necessary.
As part of the EWS throttling policy, the EWSfindcountlimit specifies the maximum result size of FindItem or FindFolder calls that can exist in memory on the CAS server at the same time for a user during a particular process. The default EWSfindcountlimit is set at 1000, which means that the default EWS throttling policy will limit the list of returned items to 1000. Since the default limit is set to 1000 and an account holds more than 1000 items, the default policy will prevent all folders from being returned for archiving. This article will explain how to change the throttling policy to allow all items to be archived.
To allow all items to be archived, the first step is to modify the throttling policy. To get the name of the throttling policy, issue the following command in the Exchange Management Shell or Windows PowerShell:
If, however, there are several throttling policies already configured, it will be necessary to determine the particular policy assigned to the mailbox of interest.
Next, run the following command to determine the name of the throttling policy assigned to a mailbox:
Get-Mailbox <mailbox name> | fl throttlingpolicy
When the results are returned and the name of the throttling policy associated with the mailbox is known, the EWSfindcountlimit can be changed by issuing the following command that will set the new EWSfindcountlimit (and the new limit chosen should exceed the number of items to be archived):
Set-ThrottlingPolicy <ThrottlingPolicyName> -EWSFindCountLimit <NewLimit>
Once the command has completed, run the Get-throttlingpolicy command again to confirm that the update was applied to the policy.
Once the new limit is set, it can take anywhere from 5 to 90 minutes for the changes to become active, depending on the size of the organization and the Exchange infrastructure. As a general rule, wait approximately thirty minutes to run an archive job on a large mailbox after updating the throttling policy, to verify that all folders can be archived.