SMTP routing based on sender address

Hi,I have a server that manage two internet mail domain, with two spearate global domain documents.

I need to route the outbound SMTP messages based on sender internet mail domain.

For example:

user@domainONE.com → outbound message routed to smtpserverONE

user@domainTWO.com → outbound message routed to smtpserverTWO

I read about foreign SMTP domain documents but i guess it wuold route based only on destination domain.

Is there any other solution?

Thanks

maximo