Splitting emails for a single domain into two
You can use transport maps
transport_maps = hash:/etc/postfix/transport
/etc/postfix/transport
[email protected] smtp:[remote.postfix.ip.address]
[email protected] smtp:[remote.postfix.ip.address]
[email protected] smtp:[remote.postfix.ip.address]
...
[email protected] smtp:[remote.postfix.ip.address]
Don't forget to create map file and restart the postfix
# postmap /etc/postfix/transport
# service postfix restart