If two or more persons are appointed corepresentatives and unless the will provides otherwise, the concurrence of all is required on all acts connected with the administration and distribution of the estate. This restriction does not apply when any corepresentative receives and receipts for property due the estate, when the concurrence of all cannot readily be obtained in the time reasonably available for emergency action necessary to preserve the estate. When a corepresentative has been delegated to act for the others, written notice of the delegation signed by the others and setting forth the duties delegated must be filed with the court. Persons dealing with a corepresentative if actually unaware that another has been appointed to serve with him or if advised by the personal representative with whom they deal that he has authority to act alone for any of the reasons mentioned herein, are as fully protected as if the persons with whom they dealt had been the sole personal representative.