noun
postpaid mail; postage paid
A postal term indicating that postage has been paid separately, often used for bulk mailings where a stamp is not affixed.
この封筒には「料金別納郵便」と印刷されている。
This envelope is printed with 'postage paid'.
Compound of 料金 (fee), 別納 (separate payment), and 郵便 (mail).