Depending on which style of phone you are using:

1. Press PROG
2. Press an unused flex co button
3. Arrow up or down on the navigator key until you see MESSAGE WAITING on the display
4. Enter mailbox number
5. Press ENTER
6. Press EXIT

More and more I am in favor of the email integration, which allows you to copy the message to multiple email addresses.

As we all know,,,everyone checks their email way more frequently than their voicemail....