Sometimes, you may receive the following error message when the number of rules exhausts the 32-KB memory limit:
For example, a rule to move messages into a folder for a single recipient takes about 660 bytes. Therefore, there is no defined limit for the maximum number of rules that can be assigned to a folder. Typically, the limit is between 40 and 50 rules per folder.
For more information about the maximum number of rules per folder in the Inbox or in a public folder in Microsoft Exchange Server 2007, visit the following Microsoft Web site:
Article ID: 147298 - Last Review: Oct 29, 2007 - Revision: 1