Mason Post Office, 144 W Ash St., 48854-9998 — All Postal operations have been suspended due to structural damage to the facility. Retail, PO Box and delivery operations have been relocated to the Lansing Main Post Office, 4800 Collins Rd., Lansing, 48924. Retail hours are Monday through Friday, 8:30 a.m. to 7:30 p.m., and Saturday, 8:30 a.m. to 2:30 p.m. An additional retail location is the Holt Post Office, 2190 Aurelius Rd., 48842-9998. Hours are Monday through Friday, 9 a.m. to 5 p.m., and Saturday, 9:30 a.m. to 2:30 p.m.