express delivery mail; special delivery post
Abbreviation of 速達郵便. Refers to mail sent by express or special delivery service.
この書類は速達便で送ってください。
Please send these documents by express delivery.
Since I was in a hurry, I sent the documents by express mail.
The book I ordered arrived by express mail.
It costs more, but I decided to use express mail.
速達郵便 is the full, formal term for express mail, and 速達便 is its everyday abbreviation.
普通郵便 is standard, non-expedited mail, in contrast to 速達便, which arrives faster for an extra fee.
Used to count 速達便 (express mail items) as pieces of mail/documents, e.g. 速達便一通.
Compound of 速達 (express delivery) and 便 (mail, service). Abbreviation of 速達郵便.