That's actually the display name of the Unity Messaging System account that Untiy uses to send outside caller messages to subscribers - you can change the display name of that object (just don't touch anything else in there) in ADUC (or Ex55) to whatever you want and it'll stick.
I'm not sure I understand your statement about the phone interface here, though... Unity doesn't read the from field for messages over the phone - it'll only play the voice name (or extension number of no voice name is recorded) of the subscriber who sent the message or say "message from an unknown caller" if it's from an outside caller. The only time you'd see this display name is via the desktop (Outlook) email interface when looking at messages.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.