Email is the transmission of messages and files between computers or smart devices over a(n) ____.

A) STMP
B) network
C) ISP
D) Web app

Email is transmitted over a network, which can be a local network or the internet. STMP (Simple Mail Transfer Protocol) is a protocol used for sending email, but it is not the transmission medium. An ISP (Internet Service Provider) is a company that provides internet access, but it is not directly involved in the transmission of email. A web app is a software application that runs in a web browser, and while it can be used for email, it is not the transmission medium.