United States Postal Service Changed Postmark Rules
A new postmark rule for the United States Postal Service took effect on December 24, 2025. The USPS postmark is an official mark that shows where and when mail was accepted by the Postal Service. Previously, when you dropped mail in a mailbox or blue postal box, you could assume that mail would be postmarked on the day you dropped it in the box—when you mailed it. With the new rule now in place, postmarks …