Hi,
only one point I really would like to change in main.cf (several others too) is mynetworks. You add:
1. the whole network of the servers IP -> 1.2.3.4/24
2. all the machines in transports -> 1.2.3.5, 1.2.3.6, ....
I really dont want to have ALL THE MACHINES of this network in mynetworks...