Hi schmerold2,
This long live bug was fixed moment ago, commit log:
https://bitbucket.org/zhb/iredmail/comm … 85af650e5c
The root cause is Dovecot reads config file location from global variable CONFIG_FILE on CENTOS 6, but it's set to iRedMail config file (/root/iRedMail-x.y.z/config) by default. It's now renamed to IREDMAIL_CONFIG_FILE instead to avoid name space conflict.