There is a method to bypass RBL checking for certain addresses and domains in Postfix. This assumes that you are using RBL checking in the first place. First, create an rbl_override file in /etc/postfix. vi /etc/postfix/rbl_override Place the domains and/or IP addresses you would like whitelisted into that file. 192.168.0.1 192.168.0.2 domain.com subdomain.example.com Create the [...]