Your voicemail doesn’t have to be monotonous or impersonal. What you need is something that is unique to you but works in a professional manner. Professional voicemails are important, because they’re an extension of your personal brand, reflecting what level of professionalism you offer. Use these voicemail greetings for work or personal cell phone messages […]
Users often don’t invest enough time into their messages, resulting in incomplete, unprofessional, or otherwise under-whelming greetings. Sure, crafting a greeting doesn’t sound all that complicated; however, there are a number of pitfalls users can fall into—i.e. informality, terseness, sincerity, lack of direction, and more. While none of these sound too catastrophic, they are often interrelated. As such, they tend to worsen any problem. For example, humor can cause informality, worsen ambiguity, and weaken sincerity. That being said, users should strive to avoid ALL these pitfalls.

Lastly, thank the caller and reassure them that their phone call will be responded to as soon as possible.
While this information can be tucked behind a phone menu option, it's best to state it upfront in your after hours recording. This way, callers can decide whether to call back at a better time, or leave a voicemail message.