mailing services.

Mailing on and off campus

On-campus mailing

Mailing Services picks up and delivers interdepartmental mail each weekday.

Campus mailing address format

On-campus mailing addresses use a PO Box number—never a street address or building name and room number. The PO Box number begins with the digits 64, followed by a unique 4-digit delivery code for each department. The delivery code also appears in the extended zip code.

How to address on-campus mail

  • Line 1: Recipient name
  • Line 2: Department name
  • Line 3: PO Box 64XXXX
  • Line 4: Pullman, WA 99164-XXXX

XXXX represents the 4-digit delivery code for the department.

Emergency mail

Pullman campus locations for emergency mail (mail that is generated after the morning pickup that is very time sensitive and limited quantities):

  • EE/ME Building  room 102 – 2:30 p.m.
  • French Administration Building room 144 – 2:45 p.m.
  • Cooper Publications Building room 40 – 4:00 p.m. (Mail is transported to the U.S. Postal Service office at 4:15 p.m.)

If you have a large outgoing mailing to be picked up, please notify us by 8:30 a.m. so the carrier will be prepared.


Contact Mailing Services at 509-335-2365 or

U.S. Postal Service rates

As of January 1, 2022

.205 per piece for letters up to 3.3 oz.

First class:
.58 per letter-sized piece weighing up to 1 oz.

Special service mailing options

Business Reply Mail

Enables a department to receive First-Class Mail back from customers and pay postage and a per piece charge only for the pieces returned. Business Reply Mail must conform to specific standards for acceptance by the United States Postal Service. Contact a project coordinator  for business reply envelopes or cards.

Certified Mail

Provides the sender with a mailing receipt and a record of delivery. Certified Mail is dispatched and handled as ordinary mail. Insurance is not provided.

Express Mail

One- or two-day guaranteed delivery service from Pullman to any location in the United States. Delivery time depends upon the location of the destination. International Express Mail service is available to most countries.

Insured Mail

Insures all mail classes in amounts up to $5,000. Contact Mailing Services for rates.

Registered Mail

Provides insurance for valuable First-Class and Priority packages. Registered mail must be sealed against tampering. Wrap and seal packages with mucilage or glue or with plain paper or cloth tape. Do not use self-sealing envelopes or slick-faced tape, such as cellophane, masking, or nylon wrapping tape.

Delivery confirmation

Need to know your mail arrived?

Priority Mail offers delivery confirmation most times at no charge. You’ll get a tracking number that lets you check online to see if the item has been delivered.

Need signature confirmation?

If you want the individual who receives the package (though not necessarily the addressee) to sign for it, your mail service options include:

  • Priority Mail
  • First-Class Mail

Need a return receipt?

Choose one of these services:

  • Certified Mail (The recipient at the delivery address signs to receive the item.)
  • Insured Mail (The recipient must sign for the item and you can be compensated if the item is lost or damaged.)
  • Registered Mail (Every person who handles the item must sign a form.)
  • Express Mail (You get one- or two-day delivery and a recipient at the delivery address signs for the item.)

International mail

Regardless of weight, there must be a customs form filled out for all international items (including APD, FPO, and DPO) that are not documents.  Contact Mailing Services for the USPS definition of what is a document.