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First Class Mail

According to University policy, campus mail should only be used to support the necessary communications of University business. It cannot be used for employees' personal purposes, political purposes, or for purposes of organizations/activities not sanctioned by the University.

See mailing rates for First Class mail

Other types of mailings:

Physical Limitations for First Class Items

Each piece of First Class/Priority Mail is limited to the following physical qualities.


  • Maximum weight: 13 ounces
  • Items weighing more than 13 ounces should be marked Priority Mail and will receive Priority Mail service


  • Maximum size: 108 total inches (length plus girth)
  • Minimum size: 5 inches long, 3.5 inches high, and 0.007 inches thick
  • Maximum size for postcard rate cards: 6 inches long, 4.25 inches high, and 0.0095 inches thick

Items under 1 ounce are subject to an $0.11 surcharge if they are:

  • Longer than 11.5 inches,
  • Higher than 6.125 inches,
  • Thicker than 1/4 inch, or
  • Do not feature an aspect ratio (length divided by height) between 1.3 and 2.5

Best Practices for First Class Mail

Mail Services processes thousands of pieces of incoming and outgoing mail each day. There are several things that your department can do to expedite your mail.

  1. Address your mail properly
  2. Prepare outgoing mail for Mail Services
  3. Design mailers according to USPS guidelines
  4. Use the University's mailing and printing resources

1. Address your mail properly

When sending mail, be sure to use the correct mailing abbreviations. See the USPS State Abbreviations for reference.

When receiving mail, provide the following return address details to senders:

  • Your name
  • Northwestern University
  • Department 
  • Building
  • Building address
  • Evanston, Illinois 60208-xxxx (Evanston mail code) or Chicago, Illinois 60611-xxxx (Chicago mail code)

2. Prepare outgoing mail for Mail Services

Outgoing U.S. mail requiring postage (and pertaining to University business) can either be left for pickup with your campus mail or brought to the mail center. The mail is weighed, posted, and taken to the Post Office.

Separate your mail into these categories before it is picked up:

  • Domestic mail that requires postage
  • International mail that requires postage
  • Stamped mail
  • Evanston campus mail
  • Chicago campus mail

Some mail must be sealed:

  • Letter-size mail does not have to be sealed, but the flaps should be left up (nested). This mail is sealed as it passes through the mailing machine.
  • Envelopes larger than letter size, as well as all international mail, should be sealed before it is given to Mail Services.

Complete a "Request for Mailing Services" form and attach barcode for all outgoing mail.
Use of this form will help your department keep track of your postage dollars and reconcile your billings. Bar code labels should be attached to the "Request for Mail Services Form" for faster processing.

3. Design mailers according to USPS guidelines

Call Evanston Mail Services at 847-491-7227 or Chicago Mail Services at 312-503-8131 before designing mail pieces to ensure proper United States Postal Service guidelines are followed.

4. Use the University's mailing and printing resources

Permit imprint can expedite mass mailings.

When postage information is pre-printed in the upper-right corner of mail pieces it is called a "permit imprint." It has no postage discount but can expedite delivery for mass mailings. It can be used when:

  • At least 200 pieces of First Class Mail or Standard A Bulk Mail are sent out
  • The items are the same size and weight, and weigh less than one pound per piece
  • The mailing does not require specially printed envelopes

By printing the proper First Class Mail indicia directly on the envelope, your mailing does not have to go through the mailing machine and can be processed faster. There is no need for special sorting by the sender; the mail can be sent to Mail Services in any order. Call Evanston Mail Services at 847-491-7227 or Chicago Mail Services at 312-503-8131 for more information on permit imprint eligibility.

Misdelivered Mail

If you receive mail that is delivered to an individual no longer in your department (but still at Northwestern) or if the mail was delivered to your department in error, complete the Evanston Misdelivered Mail Form or Chicago Misdelivered Mail Form.