How You Can Send Mail Without a Stamp

Have you accidentally forgotten to include a stamp on a letter before? Here's how you can send mail without a stamp.

Stamping Out Counterfeit Postage

Can you mail cash without stamps? - Quora

How to Send a Letter or Postcard

Postal Services International Student and Scholar Services

USPS tightens rules on stamped parcels and letters

Business Reply Mail Services — Direct Mail, Fulfillment Services, Mailing List

Can You Attach Money to a Letter Instead of a Stamp?

Italian post office: How to send a letter in Italy

The 'First Piece of Mail Sent Using a Stamp' Could Fetch $2.5 Million

Happy Mail Rubber Stamp by Paper Sushi

Royal Mail urges people to use or swap non-barcoded stamps, Saving money

How to Send Certified Mail® From Home or The Office

What is the difference between First-Class Mail and regular mail?