だい さん しゅ郵便 ゆうびん ものじゃないです
daisanshuyūbimmonojanaidesu

Noun
Desu Copula
Negation Auxiliary

The polite negative form of 第三種郵便物

1. It's not third-class mail.; It isn't third-class mail.

Negative
Polite
Casual Register