[NBLUG/talk] Postfix mail routing

[Omar Eljumaily]

Does anybody know how Postfix will route mail if a user doesn't exist on 
one of the local machine's domains?

I'm trying to set up GMail for business to handle "split delivery." Some 
of the addresses get handled by GMail and some get handled by my 
server.  I'm wondering what will happen if my Postfix server sees an 
email address that doesn't exist for my domain on that server. This will 
happen when local users send mail through it as a relay. Will it send it 
along to the proper MX record server, GMail, or will it send it back an 
error?

I know I can try this, and I will do it over the weekend regardless, but 
I was wondering if anybody knows what to expect.

Thanks,

Omar