The IMAPIFormInfo::CalcVerbSet method returns a pointer to the complete set of verbs used by a form.
See IMAPIFormInfo : IMAPIProp.
HRESULT CalcVerbSet(
ULONG ulFlags,
LPMAPIVERBARRAY FAR * ppMAPIVerbArray
);
Client applications call the IMAPIFormInfo::CalcVerbSet method to obtain a pointer to the set of verbs used by a form. Within the SMAPIVerbArray structure returned in the ppMAPIVerbArray parameter, the verbs are returned in order of index number; each verb's index is found in its lVerb member. Client applications can use the verb array to dynamically build menus, hide or show buttons, and so on.