pronounced as separate letters) Short for Simple Mail

Transfer Protocol, a protocol for sending e-mail messages

between servers. Most e-mail systems that send mail over the

Internet use SMTP to send messages from one server to

another; the messages can then be retrieved with an e-mail

client using either POP or IMAP. In addition, SMTP is

generally used to send messages from a mail client to a mail

server. This is why you need to specify both the POP or IMAP

server and the SMTP server when you configure your e-mail

application.