sendmail
Sendmail is a general purpose internetwork email routing facility that supports many kinds of mail-transfer and delivery methods, including the Simple Mail Transfer Protocol (SMTP) used for email transport over the Internet.
A descendant of the ...
, delivermail, also by
Eric Allman
Eric Paul Allman (born September 2, 1955) is an American computer programmer who developed sendmail and its precursor delivermail in the late 1970s and early 1980s at UC Berkeley. In 1998, Allman and Greg Olson co-founded the company Sendmail, I ...
, is a
mail transport agent
Within the Internet email system, a message transfer agent (MTA), or mail transfer agent, or mail relay is software that transfers electronic mail messages from one computer to another using SMTP. The terms mail server, mail exchanger, and MX host ...
that used the
FTP
The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data ...
protocol on the early
ARPANET
The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first networks to implement the TCP/IP protocol suite. Both technologies became the technical fou ...
to transmit
e-mail
Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" meant ...
SMTP
The Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients typical ...
. After
DNS
The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ...
replaced
hosts file
The computer file hosts is an operating system file that maps hostnames to IP addresses. It is a plain text file. Originally a file named HOSTS.TXT was manually maintained and made available via file sharing by Stanford Research Institute for the ...
s, DNS-style host names were also adopted.
In 1979, when ''delivermail'' was first shipped with 4.0BSD and 4.1BSD, the
ARPANET
The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first networks to implement the TCP/IP protocol suite. Both technologies became the technical fou ...
was still using
NCP
NCP may refer to:
Science and medicine
* Novel Coronavirus Pneumonia (a temporary name for COVID-19), an outbreak that was officially identified in late 2019.
* HIV-1 nucleocapsid protein 7 (NCp7), a target of zinc finger inhibitors
* Nucleosome ...
as its
network protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchroniza ...
. When the
ARPANET
The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first networks to implement the TCP/IP protocol suite. Both technologies became the technical fou ...
switched to
TCP/IP
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...
at the end of 1982, the road was paved for MTAs which used TCP to deliver e-mail; ''delivermail'' evolved into
sendmail
Sendmail is a general purpose internetwork email routing facility that supports many kinds of mail-transfer and delivery methods, including the Simple Mail Transfer Protocol (SMTP) used for email transport over the Internet.
A descendant of the ...