How can you find the IP address of an IP extension?

What is used to send out alarm notifications to you?

By which method are alarm notifications sent to an IP Office support engineer?

If no Music-on-Hold source is selected, what will a caller hear when a user places them on hold?

A customer has a Windows Voicemail Pro server. When calls come into the customer's system, if the telephone number of the caller is in the customer's records, the customer wants those calls to be routed to a specific user.
Which voicemail action type is needed to configure this?