Using a smarthost
From Veximwiki
First go to your routers section and comment out the "dnslookup" lookup router. Then you have to add the following after it:
smarthost: debug_print = "R: smarthost for $local_part@$domain" driver = manualroute domains = ! +local_domains transport = remote_smtp route_list = "* mysmarthost.example.com byname" host_find_failed = defer same_domain_copy_routing = yes no_more
Replace mysmarthost.example.com with your smarthosts address. After this mails that are not local will be delivered using mysmarthost.example.com.
TODO: Add information about authenticated smarthosts.
