I am having an issue where my SmarterMail Inbound Server running 14.1 cannot send email from a local domain user to another local domain user, without receiving the error 550 Authentication is required for relay back from the main mailserver running SmarterMail v13.5
If I setup smtp authentication bypass, than no spam filtering is done.
Here is a better explanation :
ServerA - Incoming Mail Gateway SM v14.1 receives an email from firstname.lastname@example.org and to email@example.com (Both same addresses), smtp logs show received just fine, then it goes to the delivery logs where once it says MAIL FROM:firstname.lastname@example.org immediately it is kicked back with error "550 Authentication is required for relay"
I have the incoming gateway server ip listed in whitelist (SMTP), bypass gateways.