That's a bad move.
2. Wrong. Your voice mail is protected from eavesdropping co-workers only if you have made a careful effort to select an effective password for access to it. You do not need to be in your office to receive your voice mail. You can call from home or any other location, dial a password to identify yourself, and hear your messages. The problem is that any other person calling the same number and using the same password can also retrieve your messages.
Few people take the trouble to protect their voice mail with a unique password. They do not change the default password that comes with the system when it is installed. This is often the last four digits of the telephone number or the employee's extension number followed by the pound sign. People who do change the password often use an easily guessed password such as their first or last name.
Remember that all current and former employees of your office who are or have been on the same voice mail system know the number to call to retrieve messages. If you have not changed the default password or you use an easily guessable password, they can also retrieve your voice mail messages without your being aware of it.
Related Topic: Voice Mail is Vulnerable in Spy Stories describes two cases in which individuals were prosecuted for unauthorized access to voice mail. Also see Voice Mail in the Intercepting Your Communications module.