I've partitioned our phones and built the calling search spaces as well. I'm having an issue now where the phones will not visually indicate when there is a voicemail. Generally, the handset LED would glow red, and there would be an icon on the LCD. All of my voicemail ports are in a partition, which all phones have in their assigned line CSS. In addition to that, the voicemail port partition has access to all of the phones in question.
Any phone can dial their voicemail, but they do not see the visual indicators.