Smail
Encyclopedia
Smail-3 is a mail transfer agent
(MTA) used on Unix-like
operating systems. It is freely available but is not a package under the GNU GPL. It aims to be a general and flexible mailer with extensive facilities for checking incoming e-mail
. It is still in use on the Internet
, but it has been mostly superseded by Exim
(which was originally based on Smail).
Smail-3 still follows the Sendmail
design model, where a single binary
controls all the facilities of the MTA. This monolithic design is generally considered to be inherently less secure, largely due to the lack of separation between the individual components of the system. Nevertheless, Smail's security record has been fairly clean, and has only been the subject of one BUGTRAQ
advisory.
Mail transfer agent
Within Internet message handling services , a message transfer agent or mail transfer agent or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture...
(MTA) used on Unix-like
Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
operating systems. It is freely available but is not a package under the GNU GPL. It aims to be a general and flexible mailer with extensive facilities for checking incoming e-mail
E-mail
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
. It is still in use on the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
, but it has been mostly superseded by Exim
Exim
Exim is a mail transfer agent used on Unix-like operating systems. Exim is free software distributed under the terms of the GNU General Public License, and it aims to be a general and flexible mailer with extensive facilities for checking incoming e-mail....
(which was originally based on Smail).
Smail-3 still follows the Sendmail
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 used for email transport over the Internet....
design model, where a single binary
Executable
In computing, an executable file causes a computer "to perform indicated tasks according to encoded instructions," as opposed to a data file that must be parsed by a program to be meaningful. These instructions are traditionally machine code instructions for a physical CPU...
controls all the facilities of the MTA. This monolithic design is generally considered to be inherently less secure, largely due to the lack of separation between the individual components of the system. Nevertheless, Smail's security record has been fairly clean, and has only been the subject of one BUGTRAQ
Bugtraq
Bugtraq is an electronic mailing list dedicated to issues about computer security. On-topic issues are new discussions about vulnerabilities, vendor security-related announcements, methods of exploitation, and how to fix them...
advisory.
External links
- Weird.com, Smail-3 Internet Mailer