Am 16.04.2014 19:52, schrieb sedandgrep: > The SPF record is defined only for the proxy machine and defining the actual > backend postfix would reveal the backend IP. Are you saying that in this > case SPF will not work unless I add a record for my backend postfix IP?
you need to understand SPF, TCP and networking, that's all * your machine is connectiong to the destination * the destination knows the IP you are connecting with * the SPF record has to contain that IP you reveal nothing - how do you come to that conclusion? the destination already knows the connecting IP address, you can't hide that based on how TCP works basically - your job is that in the DNS record that IP adress is listed - there is no but/if or rocket science
