remote_smtp:
driver = smtp
interface = <IP address>
interface = ${if exists {/etc/mailips}{${lookup{$original_domain}lsearch{/etc/mailips}{$value}{${lookup{$sender_address_domain}lsearch{/etc/mailips}{$value}{${lookup{${perl{get_sender_from_uid}}}lsearch*{/etc/mailips}{$value}{}}}}}}}}
helo_data = ${if exists {/etc/mailhelo}{${lookup{$original_domain}lsearch{/etc/mailhelo}{$value}{${lookup{$sender_address_domain}lsearch{/etc/mailhelo}{$value}{${lookup{${perl{get_sender_from_uid}}}lsearch*{/etc/mailhelo}{$value}{$primary_hostname}}}}}}}{$primary_hostname}}
10.10.10.10: domain1.com
10.10.10.11: domain2.com
*: domain3.com
domain1.com: 10.10.10.10
domain2.com: 10.10.10.11
*: 10.10.10.13