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When you dial into your own voicemail box in order to check your messages, there is an option to place an outbound call that we call "voicemail callout".
See Voicemail System Options for a full list of all the administrative options available within the voicemail system as well as the keypresses to navigate to these options.
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Call into your voicemail box (press the key on your phone or read How do I check or administer my voicemail remotely? if you are remote)
Press 3 for advanced options
Press 4 for voicemail callout
Follow the system prompts to dial the number you wish to call
Your outgoing Caller ID will match your company's Global Caller ID so it appears that you are calling the person from your office.
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