Beyond Linux From Scratch - Version 6.1

Chapter 22. Mail Server Software

Sendmail-8.13.4

Introduction to Sendmail

The Sendmail package contains a Mail Transport Agent (MTA).

Package Information

Sendmail Dependencies

Required

Berkeley DB-4.3.28 and Procmail-3.22

Optional

OpenSSL-0.9.7g, OpenLDAP-2.2.24, tcpwrappers-7.6, Cyrus SASL-2.1.21, nph, and AFPL Ghostscript-8.51 or ESP Ghostscript-7.07.1 (for creating PDF documentation)

Installation of Sendmail

Before building Sendmail, create the users, groups and directories that Sendmail requires with the following commands issued as the root user: 

groupadd -g 26 smmsp &&
groupadd -g 34 mail &&
useradd -c "Sendmail Daemon" -g smmsp -G mail \
        -d /dev/null -s /bin/false -u 26 smmsp &&
chmod -v 1777 /var/mail &&
install -v -m700 -d /var/spool/mqueue

Note: See the source tree sendmail/README file for information on linking optional packages into the build. Use the example below, which adds support for tcpwrappers, SASL, StartTLS (OpenSSL) and OpenLDAP, as a starting point. Of course, modify it to suit your particular needs. 

cat >> devtools/Site/site.config.m4 << "EOF"
APPENDDEF(`confENVDEF',`-DSTARTTLS -DTCPWRAPPERS -DSASL -DLDAPMAP')
APPENDDEF(`confLIBS', `-lssl -lcrypto -lwrap -lsasl2 -lldap -llber')
APPENDDEF(`confINCDIRS', `-I/usr/include/sasl')
EOF

Install Sendmail with the following commands: 

cat >> devtools/Site/site.config.m4 << "EOF"
define(`confMANGRP',`root')
define(`confMANOWN',`root')
define(`confSBINGRP',`root')
define(`confUBINGRP',`root')
define(`confUBINOWN',`root')
EOF
cd sendmail &&
sh Build &&
cd ../cf/cf &&
cp generic-linux.mc sendmail.mc &&
sh Build sendmail.cf

Now, as the root user: 

install -v -d -m755 /etc/mail &&
sh Build install-cf &&
cd ../../ &&
sh Build install &&
cp -v -R cf/* /etc/mail &&
cp -v cf/cf/{submit,sendmail}.mc /etc/mail &&
for manpage in sendmail editmap mailstats makemap praliases smrsh
do
    install -v -m444 $manpage/$manpage.8 /usr/share/man/man8
done &&
install -v -m444 sendmail/aliases.5    /usr/share/man/man5 &&
install -v -m444 sendmail/mailq.1      /usr/share/man/man1 &&
install -v -m444 sendmail/newaliases.1 /usr/share/man/man1 &&
install -v -m444 vacation/vacation.1   /usr/share/man/man1

Install the Sendmail Installation and Operations Guide with the following commands: 

cd doc/op &&
sed -i -e 's/groff/GROFF_NO_SGR=1 groff/' Makefile &&
make op.txt op.pdf

Now, as the root user: 

install -v -d -m755 /usr/share/doc/sendmail-8.13.4 &&
install -v -m644 op.ps op.txt op.pdf \
    /usr/share/doc/sendmail-8.13.4 &&
cd ../../

Note: remove op.pdf from the make and install commands if you don't have Ghostscript installed.

Command Explanations

cat > devtools/Site/site.config.m4 << "EOF": This creates a configuration file changing some of the default settings.

sh Build; sh Build sendmail.cf; sh Build install-cf; sh Build install: Sendmail uses an m4 based build script to create the various Makefile's. These commands build and install the package.

for manpage in...;do...;done; install ...: The man pages are installed already formatted and man displays them somewhat garbled. These commands replace the formatted pages with pages man can display properly.

Configuring Sendmail

Config Files

/etc/mail/*

Configuration Information

Create the /etc/mail/local-host-names and /etc/mail/aliases files using the following commands as the root user: 

echo $(hostname) > /etc/mail/local-host-names
cat > /etc/mail/aliases << "EOF"
postmaster: root
MAILER-DAEMON: root

EOF
newaliases -v

Sendmail's primary configuration file, /etc/mail/sendmail.cf, is complex and not meant to be directly edited. The recommended method to make changes is to modify /etc/mail/sendmail.mc, and various m4 files, then run the m4 macro processor from within /etc/mail as follows: 

m4 m4/cf.m4 sendmail.mc > sendmail.cf

A full explanation of the files to modify, and the available parameters can be found in /etc/mail/README.

Boot Script

To automate the running of Sendmail at startup, install the /etc/rc.d/init.d/sendmail init script included in the blfs-bootscripts-6.1 package. 

make install-sendmail
[Note]

Note

The -qNm option to sendmail, where N is number of minutes, controls how often Sendmail will process the mail queue. A default of 5 minutes is used in the init script. Individual workstation users may want to set this as low as 1 minute, large installations handling more mail may want to set it higher.

Contents

Installed Programs: editmap, hoststat, mailstats, mailq, makemap, newaliases, praliases, purgestat, sendmail, smrsh, and vacation
Installed Libraries: None
Installed Directories: /etc/mail, /usr/share/doc/sendmail-8.13.4, /var/spool/mqueue, and /var/spool/clientmqueue

Short Descriptions

editmap

queries and edits Sendmail map files.

hoststat

prints Sendmail's persistent host status.

mailstats

displays Sendmail statistics.

mailq

prints a summary of outbound mail messages waiting for delivery.

makemap

creates Sendmail map files.

newaliases

rebuilds /etc/mail/aliases.db from the contents of /etc/mail/aliases.

praliases

displays current Sendmail aliases.

purgestat

causes Sendmail to clear (purge) all its host-status information.

sendmail

is the Sendmail mail transport agent.

smrsh

is a restricted shell for Sendmail.

vacation

is an email auto responder.

Last updated on 2005-08-01 13:29:19 -0600