I have the Reputation TA installed on a universal forwarder and it is continually reporting N/A when reviewing Exchange health overview. This is a test environment so I don't really have a need for a heavy forwarder. Does the reputation TA require a full Splunk instance?
It does need Python.
See my issue here: http://splunk-base.splunk.com/answers/81213/splunk-for-exchange-smtp-reputation-script-errors
in case you find it quirky. Mine still doesn't work.
S.
I went ahead and just installed this on the central splunk instance instead. My guess is it requires Python which is only included in the full Splunk install. I didn't test installing Python manually on the Windows forwarder.