SMTP - Simple Mail Transfer Protocol
Glossary
ASCII
American Standard Code for Information Interchange.
command
A request for a mail service action sent by the sender-SMTP to the receiver-SMTP.
domain
The hierarchically structured global character string address of a host computer in the mail
system.
end of mail data indication
A special sequence of characters that indicates the end of the mail data. In particular, the five
characters carriage return, line feed, period, carriage return, line feed, in that order.
half duplex
A circuit or device capable of transmitting in two directions, but not at the same time.
host
A computer in the internetwork environment on which mailboxes or SMTP processes reside.
line
A sequence of ASCII characters ending with a <CRLF>.
mail data
A sequence of ASCII characters of arbitrary length, which conforms to the standard set in the
Standard for the Format of ARPA Internet Text Messages (RFC 822).
mailbox
A character string (address) which identifies a user to whom mail is to be sent. Mailbox
normally consists of the host and user specifications. The standard mailbox naming convention is
defined to be "user@domain". Additionally, the "container" in which mail is stored.
receiver-SMTP process
A process which transfers mail in cooperation with a sender-SMTP process. It waits for a
connection to be established via the transport service. It receives SMTP commands from the
sender-SMTP, sends replies, and performs the specified operations.
reply
A reply is an acknowledgment (positive or negative) sent from receiver to sender via the
transmission channel in response to a command. The general form of a reply is a completion code
(including error codes) followed by a text string. The codes are for use by programs and the text is
usually intended for human users.
RFC
Request For Comments. A series of technical documents written during the evolution of the Internet. Among other things, the official documentation of Internet standards are defined in different RFCs. These documents are free and are widely available.
Request For Comments. A series of technical documents written during the evolution of the Internet. Among other things, the official documentation of Internet standards are defined in different RFCs. These documents are free and are widely available.
sender-SMTP process
A process which transfers mail in cooperation with a receiver-SMTP process. A local language may
be used in the user interface command/reply dialogue. The sender-SMTP initiates the transport
service connection. It initiates SMTP commands, receives replies,and governs the transfer of mail.
session
The set of exchanges that occur while the transmission channel is open.
transaction
The set of exchanges required for one message to be transmitted for one or more recipients.
transmission channel
A full-duplex communication path between a sender-SMTP and a receiver-SMTP for the
exchange of commands, replies, and mail text.
transport service
Any reliable stream-oriented data communication services. For example, NCP, TCP, NITS.
