[exim] smtp_accept_max_per_host from comfiguration text file

Inspired by Fred Viles I got this idea this morning. I hope I have the
syntax right?


smtp_accept_max_per_host = \
${lookup{$sender_host_address}lsearch{/etc/exim/conf/max-per-host.txt}}

The file max-per-host.txt looks like:

127.0.0.1: 1000
1.2.3.4: 50
5.6.7.8: 25
*: 5

I hope I have this right. And - I have a question. How do I tect this
passing IP addresses to see how it resolves? And - I wonder if 127.*
would work for a match?