39 CFR §3021.13

1. (a)In general. If the Postal Service has issued a final determination to close or consolidate a post office, an appeal is due within 30 days of the final determination being made available in conformance with § 3021.3(b).
2. (b)Appeals sent by mail. If sent by mail, a Petition for Review must be postmarked no later than 30 days after the final determination has been made available.
3. (c)Appeals sent by other physical delivery. If sent by some other form of physical delivery, a Petition for Review must be received in the Commission's Docket Section no later than 4:30 p.m., eastern time, on the 30th day after the final determination has been made available.
4. (d)Appeals sent electronically. If submitted electronically, a Petition for Review must be received in the Commission's Docket Section no later than 4:30 p.m., eastern time, on the 30th day after the final determination has been made available.