((a)) Notwithstanding any other provision of this title, the rates of postage established for mail matter enumerated in former shall be uniform for such mail of the same weight, and shall not vary with the distance transported.
((b)) The rates of postage under former shall not be effective except with respect to mailings which—
((1)) constitute materials specified in former ; and
((2)) are sent between—
((A)) an institution, organization, or association listed in subparagraph (A) or (B) of such former section 4554(b)(1) and any other such institution, organization, or association;
((B)) an institution, organization, or association referred to in subparagraph (A) and any individual (other than an individual having a financial interest in the sale, promotion, or distribution of the materials involved);
((C)) an institution, organization, or association referred to in subparagraph (A) and a qualified nonprofit organization (as defined in former ) that is not such an institution, organization, or association; or
((D)) an institution, organization, or association referred to in subparagraph (A) and a publisher, if such institution, organization, or association has placed an order to purchase such materials for delivery to such institution, organization, or association.