Notes
How to serve direct delivery for a particular domain along with a smarthost for rest
customdelivery:
condition = ${if eq {${lc:$domain}} {themactep.com} {true} fail }
driver = dnslookup
transport = remote_smtp
or
customdelivery:
condition = ${if eq {${lc:$domain}} {themactep.com} {true} fail }
driver = manualroute
transport = remote_smtp
route_list = "* mail.themactep.com byname"
add this to /etc/exim4/conf.d/router/200_exim4-config_primary
before smarthost
entry.