KISS

Today I'm looking at monitoring the throughput of a mail server running RHEL5. Unfortunately the default check_mailq supplied with Nagios just looks at the size of the number of messages in the mailq.

Another problem I encountered was that mailq is not setuid root on this distro. Rather than reinvent the wheel, I thought I'd have a look at how RH & sendmail measure the size of the queue.

• /usr/bin/mailq is a symlink to /etc/alternatives/mta-mailq
• /etc/alternatives/mta-mailq is a symlink to /usr/bin/mailq.sendmail
• /usr/bin/mailq.sendmail is a symlink to /usr/sbin/sendmail
• /usr/sbin/sendmail is a symlink to /etc/alternatives/mta
• /etc/alternatives/mta is a symlink to /usr/sbin/sendmail.sendmail

...of course!