E-mail messages are blocked at the local delivery queue in an Exchange Server 2007 Service Pack 2 environment if a user has Outlook client-side rules totaling more than 32 kilobytes (KB)

In a Microsoft Exchange Server 2007 Service Pack 2 (SP2) environment, e-mail messages sent to a user are blocked at a local delivery queue if the following conditions are true:

• A user has many Outlook client-side rules
• The total size of the rules exceeds 32 kilobytes (KB)

This behavior causes the size of the database to grow quickly because of the large number of queued messages.

Exchange Server 2007 SP2 has a 32KB restriction if client-side rules are involved during message processing. When this issue occurs, the affected messages are repeatedly blocked and redelivered.

To resolve this problem, install the following update rollup:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.