Meeting requests are not delivered if a recipient's mailbox has exceeded the storage limit and the recipient has defined a delegate

If a Microsoft Exchange Server user sends a meeting request to another user whose mailbox has exceeded the defined per-mailbox storage limitation and who also has a delegate defined with Editor permissions for Calendar and Tasks, the sender receives a non-delivery report (NDR) similar to the following:

The Exchange Server information store does not allow Inbox Rules to start when the mailbox size limit has been exceeded.

Exchange Server 5.5

To resolve this problem, obtain the latest service pack for Exchange Server version 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: The English version of this fix should have the following file attributes or later:

Component: Directory Synchronization


This hotfix contains new functionality that can resolve this problem through a registry parameter:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\Parameter sPrivate

If this value is not 0, messages sent by rules still have the mailbox quota checked. If the value is not present or is 0, messages sent by rules ignore the mailbox quota for sending messages. Applying the latest Exchange Server 5.5 service pack does not automatically add this registry value.

NOTE: If you set mailbox quotas to rules, there may be side effects. For example, if you set a forward and delete rule, it may result in data loss, and if you set meeting requests to go only to the delegate, neither may receive the request if the mailbox is over the limit.

Exchange 2000 Server and Exchange Server 2003

If this value is not 0, messages sent by rules still have the mailbox quota checked. If the value is not present or is 0, messages sent by rules ignore the mailbox quota for sending messages. Applying the latest Exchange 2000 Server service pack or Exchange Server 2003 service pack does not automatically add this registry value.

NOTE: If you set mailbox quotas to rules, there may be side effects. For example, if you set a forward and delete rule, it may result in data loss, and if you set meeting requests to go only to the delegate, neither may receive the request if the mailbox is over the limit.

Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 3.