expression.Update(MakePermanent, Refresh)
expression Required. An expression that returns an AddressEntry object.
MakePermanent Optional Variant. A value of True indicates that the property cache is flushed and all changes are committed in the underlying address book. A value of False indicates that the property cache is flushed but not committed to persistent storage. The default value is True.
Refresh Optional Variant. A value of True indicates that the property cache is reloaded from the values in the underlying address book. A value of False indicates that the property cache is not reloaded. The default value is False.
Remarks
New entries or changes to existing entries are not persisted in the collection until the Update method has been called with its MakePermanent parameter set to True.
To flush the cache and then reload the values from the address book, call Update with the MakePermanent parameter set to False and the Refresh parameter set to True.