INFO: MAPI Is the Only Way to Programmatically Change Profiles The only supported way to modify MAPI profiles programmatically is through Extended MAPI. The values that are written into the registry by MAPI are not documented, and direct manipulation of these values through the registry application programming interfaces (APIs) is not supported. The keys and values that make up a profile are dependent on the various providers that comprise the profile. Because providers are not compelled to document the properties that they writem or their relationship to each other, modifying these values directly can have unpredictable, adverse effects.