Cloud DevOps Admin Guide

Sendmail has been included with the AIX operating system for many years now.
Despite its reputation for being difficult to administer, it is very powerful and can perform some interesting tricks. It's helped me overcome some challenges over the years.
This article shares two interesting tricks that I discovered with Sendmail on AIX.
 

To start the Sendmail daemon, use the startsrc command. For example:

# startsrc -s sendmail -a "-bd -q30m"

The –s flag specifies the subsystem to start, and the –a flag instructs startsrc to execute the subsystem with the specified arguments.
The -bd flag starts Sendmail as a daemon (running in the background) as a Simple Mail Transfer Protocol (SMTP) mail router. The –q flag specifies the interval at which the Sendmail daemon processes saved messages in the mail queue. In this example, Sendmail will process the mail queue every 30 minutes.

To start the Sendmail daemon automatically on a reboot, uncomment the following line in the /etc/rc.tcpip file:

# vi /etc/rc.tcpip start /usr/lib/sendmail "$src_running" "-bd -q${qpi}"

Execute the following command to display the status of the Sendmail daemon:

# lssrc -s sendmail

To stop Sendmail, use stopsrc:

# stopsrc -s sendmail

The Sendmail configuration file is located in the /etc/mail/sendmail.cf file, and the Sendmail mail alias file is located in /etc/mail/aliases.
If you add an alias to the /etc/mail/aliases file, remember to rebuild the aliases database and run the sendmail command with the -bi flag or the /usr/sbin/newaliases command. This forces the Sendmail daemon to re-read the aliases file.

# sendmail -bi

To add a mail relay server (smart host) to the Sendmail configuration file, edit the /etc/mail/sendmail.cf file, modify the DS line, and refresh the daemon:

# vi /etc/mail/sendmail.cf DSsmtpgateway.xyz.com.au # refresh -s sendmail

To log Sendmail activity, place the following entry in the /etc/syslog.conf file, create the log file, and refresh the syslog daemon:

# grep mail /etc/syslog.conf mail.debug /var/log/maillog rotate time 7d files 4 compress # touch /var/log/maillog # refresh –s syslogd