noun
ordinary mail; regular mail
Standard postal term for non-express, non-registered mail. In computing contexts, may refer to plain data delivery without special handling.
この書類は通常郵便で送ります。
I will send this document by ordinary mail.
通常郵便だと届くまでに数日かかります。
It takes a few days to arrive by regular mail.
Compound of 通常 (ordinary) and 郵便 (mail).