After you upgrade to Microsoft Office Outlook 2003 (or later), you may notice that some of your rules are disabled and cannot be enabled. Other rules work correctly. If you try to enable the rules that are disabled, you receive the following error message:
One or more rules could not be uploaded to Exchange server and have been deactivated. This could be because some of the parameters are not supported or there is insufficient space to store all your rules.
This problem occurs when the rules in your mailbox exceed the 32 KB limit. The rules size limit for mailboxes in all versions of Microsoft Exchange Server is 32 KB. In Outlook 2003, the size of rules extended to add support for the Unicode format.
Start the Exchange 2010 PowerShell management console.
Powershell command to view the current rules quotas for a mailbox.
Get-Mailbox firstname.lastname@example.org |FL displayname, rulesquota
Powershell command to set the new rule quotas for a mailbox.
Set-Mailbox email@example.com -RulesQuota:256kb