Check Mailbox
Messages
This menu option should be selected if you have mailbox messages
waiting and/or if you need to record your mailbox OGM. If a caller presses 0 and
if you have set Mailbox as the Call Transfer Method (on the Transfer
Options tab of the Call Options dialog box), then the caller will be able
to leave a voice mail message for you. You will know that you have messages waiting
if you see "Mailbox has Messages!" in the title bar.

Click on a name in the list, then click the Play button to hear the message they
left for you. To record your mailbox outgoing message (this is different from
the main message you used for your call session and will only be heard by those
who choose to leave you a voice message in your mailbox), click the red Greeting
button, then click Stop when finished recording. For example: "Please leave
your message after the beep and press pound when done." Click the green Greeting
button to listen to your outgoing message, and use the Volume Slider to adjust
volume, if necessary. Note: this feature will only work if you have Mailbox selected
on the Transfer tab of the Call Options dialog.