You might also consider giving them the option to skip your voicemail message completely by pressing another key (again, check with IT). You also want to make callers aware what you will return their call, instead of telling them that you will try to return their call--and let them know when you are likely to do it, if possible. If necessary, provide additional or emergency information in your voicemail greetings. My dentist, for example, lists his cell phone number for emergencies.
But with integration being at the heart of VoIP and UCaaS, you can't make a purchasing decision here without thinking about the future. On one side, consider each vendor carefully to see what they've done over the last half-decade in terms of product development and keeping up with VoIP and UCaaS trends. On the other side, think about what you'll need in the next five years.

We’re all familiar with this type of voicemail greeting. Simply put, a caller reaches you by dialing your number or extension directly. For an optimal personal voicemail greeting, be clear about who you are, the team you’re on, and when the caller can expect a callback. Unlike company and department voicemail greetings, you may not be able to configure a greeting for open and closed business hours. If that’s the case, use a general voicemail greeting that accommodates both scenarios.
When you ditch the traditional landlines for a cloud-based PBX, you’re bound to have some questions about your new virtual business phone system. Trained technical support over the phone is a very welcome feature. After you set up the system you will have some questions about the new environment. So it’s helpful when a company offers explanatory articles on its website, and - even better - hands-on support from customer care agents. Bearing these requirements in mind, we evaluated the providers based on the availability and quality of customer support.