[exim] How to determine address of network by IP address of …

One more question about hostlists.

I have

hostlist nets = 10.10.10.0/24 : 20.20.20.0/24
...

acl_check_rcpt:
    accept
        hosts = +nets

Remote relay connects from host 10.10.10.1.

How I can determine address of network which contains 10.10.10.1 after
such 'hosts' condition succeeded?

Thanks.

-- 
Kind Regards,    Alexander Shikoff
minotaur@???
Mob.: +380 67 946 31 49