noun, noun or participle which takes 'suru', transitive verb
express mail; special delivery
Refers to the postal service for faster delivery, or the act of sending something by express mail. Commonly used as a noun or with する to mean 'send by express'.
この書類を速達で送ってください。
Please send this document by express mail.
速達にすると、明日には届
If you send it express, it will arrive tomorrow.