Не работает плагин exim_mailqueue в Munin

У меня в CentOS 7 не работал плагин exim_mailqueue, который проверяет очередь писем в exim.

В дебаге:
# munin-run exim_mailqueue --debug
# Processing plugin configuration from /etc/munin/plugin-conf.d/amavis
# Processing plugin configuration from /etc/munin/plugin-conf.d/df
# Processing plugin configuration from /etc/munin/plugin-conf.d/fw_
# Processing plugin configuration from /etc/munin/plugin-conf.d/hddtemp_smartctl
# Processing plugin configuration from /etc/munin/plugin-conf.d/munin-node
# Processing plugin configuration from /etc/munin/plugin-conf.d/postfix
# Processing plugin configuration from /etc/munin/plugin-conf.d/sendmail
# Setting /rgid/ruid/ to /99/99/
# Setting /egid/euid/ to /99 99/99/
# Setting up environment
# About to run '/etc/munin/plugins/exim_mailqueue'
exim: permission denied
Error closing pipe: 
frozen.value U
mails.value U

Решение:

# vim /etc/munin/plugin-conf.d/exim

[exim*]

user root

env.logfile maillog

env.logdir /var/log

# systemctl restart munin-node

# munin-run exim_mailqueue

frozen.value 28

mails.value 23