In an Exchange Server 2007 environment, a named property that is used to map X-headers during a message is processed at the mailbox store level. However, the named property has a size restriction. When many X-headers are promoted to named properties and the quota limitation is reached, unexpected problems occur. For example, messages from a specific domain cause the following NDR:
#550 5.2.0 STOREDRV.Deliver: The Microsoft Exchange Information Store service reported an error. The following information should help identify the cause of this error: "MapiExceptionNamedPropsQuotaExceeded:16.18969:C0000000
When this issue occurs, the following event message is logged in the Application log on the Exchange server.
Event Type: ErrorEvent Source: MSExchangeISEvent Category: General Event ID: 9667Description:Failed to create a new named property for database "<Storage Group name>\<Mailbox Store name>" because the number of named properties reached the quota limit (8192).User attempting to create the named property: "<name>"Named property GUID: <GUID>Named property name/id: "<ID>"
If you check the previous application event logs, you may find that many 9873 events that resemble the following message are logged:
Event Type: InformationEvent Source: MSExchangeISEvent Category: General Event ID: 9873Description:A named property has been created for the database "<legacyExchangeDN of the mailbox store>".ID: <ID> Named property GUID: <GUID>Named property name/ID: <name>The following user is attempting to create the named property: "N/A"Protocol: <protocol name>Client type: TransportClient version: <version number>
To resolve this problem, install Update Rollup 8 for Exchange 2007 Service Pack 1.
For more information about Update Rollup 8 for Exchange Server 2007 Service Pack 1, see the following Exchange Help topic:
Note After you apply the hotfix to the Exchange server, the Exchange 2007 server does not promote new X-headers from unauthenticated submissions, embedded messages, and journal messages. However, the X-headers requests that are submitted by authenticated clients can be still promoted. Also, later unauthenticated submissions will still process the values of X-headers because any subsequent messages that include the same X-header do not create additional named properties.
For more information about the impact of named property limits on Exchange databases, visit the following Microsoft Web site:
An X-header is a unofficial header field that exists in the message header. X-headers are not specifically mentioned in RFC 2822. However, an undefined header field that starts with "X-" is an accepted way to add unofficial header fields to a message. Messaging applications, such as anti-spam, antivirus, and messaging server applications, may add their own X-headers to a message. X-header fields are usually preserved but ignored by messaging servers and clients that do not use them.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.