When installed on Ubuntu 20.04 LTS, Virtualmin configures Postfix to use
milter_protocol = 2
which works for OpenDKIM.
But I also added Rspamd to block spam during incoming smtp, and that requires manually editing /etc/postfix/main.cf to set milter_protocol = 6.
Ordinarily this would be a harmless manual tweak.
However, any time DKIM is re-initialized, Virtualmin silently changes milter_protocol back to 2, and Rspamd breaks.
So here’s a suggested fix: Initialize milter_protocol to any desired level when Virtualmin is initially installed, but don’t change it subsequently. The idea is to not override a manual tweak.
Yes, this is correct, currently it’s hard-coded and forced to be set to value 2. @Jamie Jamie, should we not forcefully change the value, if directive already exists, but only if DKIM is not re-enabled. If it’s disabled and then re-enabled again, we can assume safely setting it to 2. If it’s just regular add new domain process, then we could respect currently set value.