SMTP or Simple Mail Transfer Protocol

Relates to how email is transmitted between hosts and users in a TCP/IP network. A mail program—such as Microsoft Outlook—sends an outgoing message to an SMTP server typically provided by the Internet Service Provider of the user. This SMTP server connects to an SMTP server at the email’s destination, where an SMTP transfer agent receives the message and puts it into the receiver’s mailbox.

See Also: Electronic Mail or Email; TCP/IP or Transmission Control Protocol/Internet Protocol.