[exim] Log Messages

Hi all,

Is there any way to insert messages into the log file (mainlog) from a
router or transport?

I have been tinkering with the 'debug_print' but do not want to run in -v
mode.

What I am specificaly looking to do is monitor the outgoing ip address
(interface) that specific routers and transports are uing, but knowing how
to add messages, log_write(s) or debug statements in routers and transports
would be of great use.

-Grant