[j-nsp] Looking for paid config - source/port NAT?

[Markus]

Am 05.08.2015 um 16:17 schrieb Michael Loftis:
> You can do a transparent proxy type setup. Using the firewall filter syntax
> to change the next hop to a properly configured Linux, FreeBSD, or whatever
> host.

The mail gateway I want to relay through is somewhere on the internet. 
In this case changing the next-hop will not be sufficient, or will it?

I tried it by using these examples:
http://www.ip-performance.co.uk/blog/juniper_bluecoat_transparent_proxy

But it didn't work.

Thank you!