[exim] Domain filtering in router

Hello,

I have this router:

noscan_router:
driver = redirect
condition = ${if match_ip{$sender_host_address}{192.168.1.21}}
domains = +local_domains
data = ${lookup mysql{select maildir from users where
id='$local_part@$domain' and block < 1}{$value}fail}
directory_transport = virtual_delivery
file_transport = virtual_delivery

With this router IP 192.168.1.21 can send mails and "bypass" content
filter setup but it can send mails to all domains, I want it could send
mails only to local_domains and If it sends a mail to a external domain
this mail must be scanned.

Maybe local_parts = *.local_domains could be an option ? I tested this
option wiht unsucessful result.

Thank you.