The following is with the assumption that you have Unified Messaging already configured:
1) Never receive notification on his desk phone - In his Unity Connection VM Box account, go to Edit > Message Waiting Indicators and uncheck "Enabled", then Save.
2) Auto delete them from Unity - Set up a Message Aging Policy to automatically have New Messages become Saved Messages, then become Deleted Messages. The policy will also allow you to set a Tombstone period (during which deleted messages can be undeleted, and after which the messages are removed from the message store). If you don't want messages to tombstone, there is an option in Class of Service to "delete messages without saving to the deleted items folder". Once they're deleted, they're gone.
If you don't have Unified Messaging already configured, another option would be to configure SMTP Relay instead. In that case set a "Message Action" to "Relay" (rather than Accept and Relay) and indicate an email address. CUC does not store those messages in the Message Store at all, but that runs the risk of having an email fail and the voicemail lost. However, you could set Accept and Relay and set a Message Aging Policy too.
If you need more clarification on this or have questions, let us know.
Maren
