[exim] Relaying and smarthosts

Hello All,

I am relatively new to exim and have a couple of questions. I am using
4.5.2 and need to permit a c-class of IP addresses to relay through my
server. I also need to set my server up as a smarthost relaying
outbound mail to the same c-class. Could someone please help me out
with a snippet/sample or two showing how this can be done? I have try
some "best guessing" attempts from the documentation to no avail.

Any help would be gratefully appreciated!

Thank you in advance.
Eric