United States Post Office 401 Church St, O Fallon, MO63366 This United States Post Office serves the 63366 Zip Code portion of O'Fallon. It is a full service post office but…More you can skip the postal clerk by using one of the two self-service machines in the lobby. It also rents PO Boxes with 24-hour access. Outside there is a drive through lane with mail boxes to drop letters in.
The Mail Depot 3023 Highway K, O Fallon, MO63368 Mail Depot can help you ship items via UPS, take your passport photos and provide you with shipping supplies. Going here…More is often quicker than visiting the post office. The staff is very friendly and will provide shipping price quotes.