Are you asking how to find the ip address for the Unity server used for a particular site? When you press the messages key, the phone dials a Hunt Pilot DN which will be shown on the phone screen. If you look in Callmanager Administration under Route Plan -> Route/Hunt -> Hunt Pilot, you will find this Hunt Pilot DN. Click the Hunt Pilot, click Edit next to the Hunt List, then click the Line Group name under Hunt List Details. Click one of the numbers listed under Directory Numbers. The IP Address listed here will be the IP address of the Unity server for this site.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...