Well i've got the following question:

On machine 1 should run postfix. machine 2 and 3 are the next hops, but they should receive mails for different domains.

following entries are mentioned in the transport-file:

example1.com smtp:[ip of machine2] example2.com smtp:[ip of machine3] example3.com smtp:[ip of machine2] example4.com smtp:[ip of machine2]

At the moment the complete mails are going to machine 2, because of the entry relyhost=[ip of machine2] in main.cf and there is no pointer to the transportfile in the main.cf.

By setting the pointer "transport_maps = hash:/etc/postfix/transport" should i comment the relyhost parameter? (#relyhost...) Or reads postfix automatically the transport file when the path to it is mentiond, whether relyhost is commented or not? What should i edit to the master.cf?

thx a lot