In order to ensure customer satisfaction, it is not only important how a business records their outgoing voicemail greeting, but also how they respond to incoming messages. It has been reported that most individuals do not mind leaving voicemail messages, but they can often become frustrated and disheartened when a business does not return their call in a timely manner or ignores the voicemail altogether.
Obviously, I need to update it. And if you haven't changed your voicemail greeting in over a year, you're likely in the same boat.

“Good afternoon. You have reached the office of [your name]. I will be out of the office beginning on [date] and will be returning on [date]. Please leave a brief message with your contact information, and I’ll be sure to get back to you as soon as I return on [date]. If this is an emergency or you need to speak with someone before I return, please contact [name of colleague/supervisor], [their job title], at [their phone number].”
When on vacation, provide your callers with a return date and a back-up contact person to accommodate emergencies. This prevents you from potentially damaging a valued relationship while you enjoy some time off.