Publication 417, Nonprofit USPS Marketing Mail Eligibility: Nonprofit and Other Qualified Organizations > 5 Cooperative Mailings > 5-3 Ineligible Mailings
Mail matter associated with joint enterprises between an authorized organization and a commercial enterprise (or other unauthorized mailer) is ineligible for the Nonprofit USPS Marketing Mail prices. Typically, ineligible cooperative mailings are arranged as follows:
Example: Ineligible Cooperative Mailing