If the intended addressee is the CMRA itself, it may refuse the mail in compliance with DMM regulations regarding "refusal of mail." However, a CMRA is unable to refuse mail for it's customers because the customer is the addressee, not the CMRA agent.
It is a long-standing Postal policy that only addressees can refuse mail, and the CMRA agent is not the addressee. Form 1583 on file at the CMRA and the Post Office, obligates the CMRA to accept its customer's mail and retain it for collection or re-mail it to the addressee, prepaid with new postage for at least 6 months after the termination date of the agency relationship between the CMRA and addressee. The CMRA and their customers agree that all mail delivered to the agency will require new postage when re-deposited in the mail.
This re-mailing obligation need not be fulfilled if the CMRA customer provides written instructions to the CMRA that the mail (or specific types of mail) not be re-mailed upon termination of the relationship. This instruction may be provided in an internal service agreement between the customer and CMRA or by a separate document. Written instructions from the customer regarding the handling of this mail must not stipulate that the CMRA refuse mail or return it to sender, or keep the mail during the 6-month re-mail period and return it to the Post Office, or redeposit mail in the mail stream without new postage.
The CMRA may refuse First-Class Mail only, for former customers, six months after the relationship terminates. When this happens, the CMRA endorses the mail and gives it to the mail person or returns it to the Post Office without payment of new postage.