> hello steve an john
> i understand you , and about collateral spam, but in this way
> access to the internal server has only the incoming
> mailserver, the internal
> server would then be reject the mails where the users are not
> available or
> not.
You could look at doing rcpt verification callouts for the email you're passing
to the internal server. Have a look at chapter 40 of the Exim docs - 40.36 and
40.37 to be more precise
http://www.exim.org/exim-html-current/doc/html/spec_html/ch40.html#SECTcallver
As long as your internal mailhost then rejects invalid emails at SMTP time, you
should be OK.
As for your original question, you want to look at using a manualroute router.
http://www.exim.org/exim-html-current/doc/html/spec_html/ch20.html
Remember that routers are run in the order they're defined in your config.
You want something like
smart_route:
driver = manualroute
domains = (some way of restricting the router to only handle the domains you
want)
transport = remote_smtp
route_list = * your.internal.mailhost's.IP.address
close to the top of your routers, I guess.
Have a read of the sections I've given you links to - hopefully you should get
an idea of how this works. If you have any further questions, post them to the
list.
Cheers,
John