I also am using opensmtpd, and have been for years. Even setting up starttls encryption and a DKIM proxy were simple. I have never had an issue with accidentall

I also am using opensmtpd, and have been for years. Even setting up starttls encryption and a DKIM proxy were simple. I have never had an issue with accidentally setting it up as an open relay or anything else that would place me on a blacklist.