Seamless mailers may change the date of finalization in case of printing or internal delays.
Eligible Mail Classes:
• First-Class Mail cards, letters, and flats
• USPS Marketing Mail, letters and flats
• Bound Printed Matter, flats
• Periodicals, letters and flats
Resources:
Mailing & Shipping Solutions Center (MSSC) Help Desk
• Phone: 1-877-672-0007 • Email: MSSC@usps.gov