How can I configure Postfix to ignore relayhost for some domains?

Is there a way in Postfix to ignore the relayhost?

I have something like

relayhost = [smtp.domain.net]:587

Now for a certain domain I don't want to send it out to that relay but want it to just send from that machine.

How do I have to configure Postfix to do that?

Solution 1:

main.cf
#relayhost = [smtp.domain.net]:587
transport_maps = hash:/etc/postfix/transport

/etc/postfix/transport
domaintodeliverdirectyto :
* smtp:[smtp.domain.net]:587

Don't forget to postmap /etc/postfix/transport

May want to use relay instead of smtp as the transport mechanisim.
For reference http://www.postfix.org/transport.5.html