It’s ok for testing. If it works you should write the settings to /etc/rspamd/override.d/phishing.conf to not change default settings of rspamd that could be overwritten in future:
http://docs.nethserver.org/en/v7/rspamd.html#modify-the-settings-of-a-module
I found a thread with a similar problem, the solution seems to be the bayes filter.