[exim] local_interfaces option

I'm trying to configure Lyris ListManager to work on a redhat server
with exim installed. I need to have ListManager on port 25 and exim
on port 26 on one IP address. Exim will need to monitor port 25 for
the other IP addresses. Is the following syntax correct for the
local_interfaces directive to accomplish this:

local_interfaces = aa.bbb.ccc.dd.26:127.0.0.1:0.0.0.0

Is the 127.0.0.1 entry necessary? I appreciate any input. This is a
new venture and my first encounter with exim.

Patrick