Knox County Post Office

Find Knox County Maine post offices and USPS mailing boxes. Post offices provide information on bulk mail services, domestic mail delivery, international shipping, change of address, mail forwarding, PO boxes, and passport services.


Camden Post Office 28 Chestnut Street Camden ME 04843 207-236-3570


Cushing Post Office 384 Pleasant Point Road Cushing ME 04563 207-354-8014

Friendship Post Office 71 Harbor Road Friendship ME 04547 207-832-7558

Matinicus Post Office 50 South Road Matinicus ME 04851 207-366-3755

North Haven Post Office 27 Main Street North Haven ME 04853 207-867-2244

Owls Head Post Office 5 Main Street Owls Head ME 04854 207-594-7535

Port Clyde Post Office 860 Port Clyde Road Saint George ME 04860 207-372-6693

Rockland Post Office 21 Limerock Street Rockland ME 04841 207-596-6461

Rockport Post Office 223 Union Street Rockport ME 04856 207-236-8809

South Thomaston Post Office 8 Elm Street South Thomaston ME 04858 207-594-7400

Spruce Head Post Office 11 Post Office Road Saint George ME 04859 207-594-7647

Tenants Harbor Post Office 4 Main Street Saint George ME 04860 207-372-6301

Thomaston Post Office 135 Main Street Thomaston ME 04861 207-354-2420

Union Post Office 309 Common Road Union ME 04862 207-785-3734

Vinalhaven Post Office 42 East Main Street Vinalhaven ME 04863 207-863-4620

Warren Post Office 21 Main Street Warren ME 04864 207-273-2411

Washington Post Office 11 Liberty Road Washington ME 04574 207-845-2412

West Rockport Post Office 642 West Street Rockport ME 04856 207-236-8285

What Change of Address options are available?

Customers can request a temporary or permanent Change of Address either online or in person at the Post Office using PS Form 3575. The online application for Change of Address has a $1.00 identity validation fee.

Is it possible to insure mail and items sent via the USPS?

Yes. Standard mail can be insured for up to $5,000 for an additional fee. Registered mail items can be insured for up to $50,000.

What is the USPS Office of Inspector General?

The Office of Inspector General (OIG) is a division within the USPS responsible for ensuring the integrity and accountability of the postal service. It conducts investigations to safeguard the postal system and performs audits and reviews.