USAGE: 郵便 refers to the postal system and the mail it delivers.
COMMON PATTERNS:
- 郵便局 (post office)
- 郵便番号 (postal code, zip code)
- 郵便受け (mailbox - for receiving)
- 郵便ポスト (mailbox - for sending)
- 郵便配達 (mail delivery)
- 航空郵便 (airmail)
- 速達郵便 (express mail)
CONTRAST: