Mailing letters and packages can get confusing and we want to help you with that. This page has some helpful hints and tips to assist you in your mailing adventures.

Abbreviations     Address Format     Address Placement     International
Mail Dimensions      Overnight     Which Box?    Zip Codes   Contact Us


  BoulevardBLVD CircleCIR
  CT DriveDR
  Lane  LN PlacePL
  Road  RD StreetST
  Terrace  TER TrailTR
  Apartment  APT FloorFL
  Room  RM SuiteSTE

*Full list of official USPS abbreviations



-- Fill out the Customs Form (you must list everything in the box)

-- Be sure to check what can be mailed to the country of destination (some countries have restrictions)

-- All international packages go out the next business day

-- When mailing to Africa you will need a PO box AND a phone number


Mail Piece Dimensions

USPS Domestic Mail Piece Dimensions

ShapeMin.Max.Max. Thickness
Large Envelopes


Overnight Shipping

-- Packages must be to Seawolf Postal Express by noon to be delivered the next day

-- Overnight shipping is not available for international shipping

-- Overnight shipping cannot be delivered to PO boxes


Which Box?

This is a general rule of thumb for knowing whether to use a flat rate box or priority. Please note that there is always an exception to the rule. Please call if you have any questions.

AK Zip Codes 998/999
-- Treat as if mailing to Lower 48's

AK Zip Codes 995/996/997
-- Up to 5 lbs use priority
-- Over 5 lbs use flat rate box


Zip Codes

Zip codes were first introduced in 1963 and are used to help route mail more efficiently. The zip + 4 was later added and helps more precisely group mail for delivery. If you need help in discovering a zip code go to the USPS' website.

Address Format

Delivery Address Order:
Line 1 - Name of Addressee
Line 2 - Street Address and Unit Number (ex. 123 Main St, APT 1) or PO Box
Line 3 - City, State and ZIP Code

Delivery Address Order for Businesses:
Line 1 - Name of Addressee
Line 2 - Company
Line 3 - Street Address and Unit Number (ex. 123 Main St, STE 10)
Line 4 - City, State and ZIP Code

APO/FPO/DPO Delivery Address Order:
Line 1 - Service Member's Full Name
Line 2 - Include the unit
Line 3 - APO/FPO/DPO (Air/Army PO, Fleet PO or Diplomatic PO) with the 9 digit ZIP Code (if one is assigned)
*All mail must be addressed to someone specific; addressing mail to "Any Service Member" is no longer permitted.

International Delivery Address Order:
Line 1 - Name of Addressee
Line 2 - Street Address or PO Box Number
Line 3 - City or Town, Other principle subdivision (such as Providence, State, or County) and Postal Code
Line 4 - FULL COUNTRY NAME (uppercase letters in English)


Address Placement

The delivery address, return address, and postage should all be on the same side of the envelope/package

Return Address
Address should be in the upper left hand corner

Delivery Address
Address should be in the center of the envelope/box, parallel to the longest side

Place postage in the upper right hand corner

Address Placement


Contact Us

Seawolf Postal Express

(907) 786-1108