I am using Postfix on OPNSense as a Smart Host for my local servers to relay mail for notifications. When I first set it up, it would spam System: Log Files: General
with the following message:
postfix/smtpd[67716] OTP unavailable because can't read/write key database /etc/opiekeys: Permission denied
I was unable to find the setting causing this issue for the longest time. Since the postfix relay otherwise worked, it seemed to be mostly an annoyance. It did render that particular log almost completely useless, however.