Outlook named properties are not supported by MAPI or CDO (266353)


The information in this article applies to:

  • Microsoft Extended Messaging Application Programming Interface (MAPI)
  • Microsoft Outlook 2002
  • Microsoft Outlook 2000
  • Microsoft Outlook 98
  • Microsoft Outlook 97
  • Collaboration Data Objects (CDO) 1.21
This article was previously published under Q266353

SUMMARY

The Messaging Application Program Interface (MAPI) provides a facility for assigning names to properties, for mapping these names to unique identifiers, and for making this mapping persistent. Microsoft Outlook writes many Outlook-specific fields into these named properties, with identifiers in the 8000-FFFE range. The Outlook Object Model is the only supported method of accessing these named properties. Access to these properties by using MAPI or Collaboration Data Objects (CDO) is not supported.

MORE INFORMATION

Named properties are identified by a name and a global unique identifier (GUID) for a property set. The name can be either a number or a string. These properties are manipulated by using the IMAPIProp::GetIDsFromNames and IMAPIProp::GetNamesFromIDs functions. The GUID and name are passed to GetIDsFromNames to obtain a property ID which is valid for the current MAPI session. Because this property ID can vary from computer to computer, the only consistent way to access a named property is to know its property set and name.

Named properties are generally used by clients as a way to add extra information to a message which is only to be used by that client. As such, none of the named properties used by Outlook clients are documented. The only supported way to retrieve these properties is through the Outlook Object Model, if they are exposed there.

Summary of supportability

Messages (Ipm.note)Messages are native to MAPI. Outlook does maintain a few named properties on these items.
Contact items (Ipm.contact)Contacts are not native to MAPI. Since contacts are like address book entries, some address entry tags will be valid. Most contact properties are named properties.
Task items (Ipm.task)Tasks are not native to MAPI. Most task properties are named properties.
Appointment items (Ipm.appointment)Appointments are not native to MAPI, but are native to CDO. Most appointment properties are named properties. Some are exposed through CDO's AppointmentItem object.
Journal items (Ipm.activity)Journals are not native to MAPI. Most journal properties are named properties.
Note items (Ipm.stickynote)Sticky notes are not native to MAPI. Most sticky note properties are named properties.


In addition to those properties that are native to MAPI and CDO, user-defined fields on customized Outlook forms are supported through MAPI, CDO, and the Outlook Object Model. These fields use PS_PUBLIC_STRINGS as the property set identifier, and the name of the field as the property name.

REFERENCES

For additional information about named properties, visit the following Microsoft Developer (MSDN) Web site:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/mapi/html/838aafb5-13d1-4ab9-860a-2398d885b5c7.asp

Modification Type:MajorLast Reviewed:5/26/2006
Keywords:kbinfo kbMsg kbOutlookObj KB266353
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