Read the quota_exceeded_message from a file

Greetings,

I've been trying to have quota_exceeded_message read from a file according to https://wiki2.dovecot.org/Quota/Configuration#Custom_Quota_Exceeded_Message ; I'm running dovecot 2.2.10 on Centos 7. If I set text right to the equal sign, it works fine, but I'd rather load it from a file as I need a new line and %n and \n and simple \ followed by a newline are not working and would understandably crash the processes if malformed.

nothing special about my setting, the file is located in the /etc/dovecot directory but separate from the config files (not in the conf.d directory), with a world readable permission.

Regards,

M.