SENDMAIL
TM
INSTALLATION AND OPERATION GUIDE
Eric Allman
Claus Assmann
Gregory Neil Shapiro
Sendmail, Inc.
Version 8.699
For Sendmail Version 8.13
Sendmail
TM
implements a general purpose internetwork mail routing facility under the UNIX® oper-
ating system. It is not tied to any one transport protocol -- its function may be likened to a crossbar switch,
relaying messages from one domain into another. In the process, it can do a limited amount of message
header editing to put the message into a format that is appropriate for the receiving domain. All of this is
done under the control of a configuration file.
Due to the requirements of flexibility for sendmail, the configuration file can seem somewhat unap-
proachable. However, there are only a few basic configurations for most sites, for which standard configu-
ration files have been supplied. Most other configurations can be built by adjusting an existing configura-
tion file incrementally.
Sendmail is based on RFC 821 (Simple Mail Transport Protocol), RFC 822 (Internet Mail Headers
Format), RFC 974 (MX routing), RFC 1123 (Internet Host Requirements), RFC 1413 (Identification
server), RFC 1652 (SMTP 8BITMIME Extension), RFC 1869 (SMTP Service Extensions), RFC 1870
(SMTP SIZE Extension), RFC 1891 (SMTP Delivery Status Notifications), RFC 1892 (Multipart/Report),
RFC 1893 (Enhanced Mail System Status Codes), RFC 1894 (Delivery Status Notifications), RFC 1985
(SMTP Service Extension for Remote Message Queue Starting), RFC 2033 (Local Message Transmission
Protocol), RFC 2034 (SMTP Service Extension for Returning Enhanced Error Codes), RFC 2045 (MIME),
RFC 2476 (Message Submission), RFC 2487 (SMTP Service Extension for Secure SMTP over TLS), RFC
2554 (SMTP Service Extension for Authentication), RFC 2821 (Simple Mail Transfer Protocol), RFC 2822
(Internet Message Format), RFC 2852 (Deliver By SMTP Service Extension), and RFC 2920 (SMTP Ser-
vice Extension for Command Pipelining). However, since sendmail is designed to work in a wider world,
in many cases it can be configured to exceed these protocols. These cases are described herein.
Although sendmail is intended to run without the need for monitoring, it has a number of features
that may be used to monitor or adjust the operation under unusual circumstances. These features are
described.
Section one describes how to do a basic sendmail installation. Section two explains the day-to-day
information you should know to maintain your mail system. If you have a relatively normal site, these two
sections should contain sufficient information for you to install sendmail and keep it happy. Section three
has information regarding the command line arguments. Section four describes some parameters that may
DISCLAIMER:
This documentation is under modification.
Sendmail is a trademark of Sendmail, Inc.
Sendmail Installation and Operation Guide
SMM:08-1