Southeastern Pennsylvania
 Southeastern was a United States Postal Service regional Processing and Distribution Center (P&DC) in Tredyffrin Township Chester County Pennsylvania United States near Devon. It was primarily known for its post mark on mail originating in many ZIP codes in the region. The retail post office remains open at the location of the former P&DC. Many bills for Verizon Communications and Comcast as well as statements from The Vanguard Group are sent from this post office.