PRB: CDO (1.x) Error MAPI_E_NOT_FOUND Setting Value of Property

When attempting to set the value of a field (property) of a Collaboration Data Objects (1.1, 1.2, 1.21) object, the following error may occur:

The field probably does not yet exist in the underlying Messaging Application Programming Interface (MAPI) object.

Instead of just setting the field value, proceed from the assumption that the field does not exist. Use the Add method of the Fields collection, which facilitates both adding the field and setting the value as follows: The sample above demonstrates adding and setting the value for the PR_EXPIRY_LIMIT (&H00150040) field. No error occurs if the property already exists.

This behavior is by design.