Website: https://www.snaprecordings.com/blog/6-tips-for-recording-professional-voicemail-greetings
“Hi, you’ve reached [your name]. I’m away from[date] to [date]. If you need help with [X] before then, please contact [name] at [phone number]. Everyone else, please leave your name and number and I’ll return your call when I return. Thanks and have a great day.” “Hello, you’ve reached [your name]. I’m currently [exploring Asia, hiking through the jungle in Costa Rica, hanging out on the beach in Bermuda] — or more likely, [recovering from extreme jet lag, googling ‘Are red spiders poisonous,’ or looking for SPF 150 sunscreen] and won’t be back in the office until [date]. Leave your contact info and reason for calling and I’ll get in touch then.” “Hey there, this is [your name] from [your company]. I’m out of the office until [date]. In the meantime, please direct your inquiries to [coworker’s name] at [email address]. [He, she] can also be reached at [phone number]. Thank you.”

The most important aspect of a voicemail message is that the listener must be able to understand your message. Don’t mumble your words and be sure to speak loudly and clearly. Speaking softly will make it difficult to understand you and may result in the listener not being able to call you back.
The simple truth is that you need to be more aware of what you’re leaving for other people to hear. Sure, this doesn’t always register as a priority for users, but it’s never too late to reassess your greeting. a. Reading/Speaking in the Imperfect Tone: Tone is absolutely everything. Users don’t want to come off as being too nice, as it sounds insincere, or being too terse, as it can be interpreted as being rude. That being said, striking the right balance is absolutely essential. Your greeting exists as its own entity, and therefore, it should NOT rely on callers’ familiarity with you. Instead, it needs to appeal to the masses. As such, your inflection, i.e. the way you state your name and directions, needs to be both welcoming and firm. b. Injecting Humor & Insincerity: While humor/light heartedness can be welcoming, it can also convey a sense of informality, insincerity, and ultimately unprofessionalism. Why, because you’re not there to lend your humor or to contextualize. Instead, you’re assuming the caller has a working knowledge of your personality to ground the message. Though this might not sound like it’s all that terrible—it can be detrimental. As stated above, one should NEVER rely on a caller’s familiarity with you. Instead, aim to appeal to the masses. Humor is ultimately subjective, meaning not everyone has the same tastes; therefore, someone is bound to be turned off by a quirky or off-color remark. While implementing a light-hearted or even tongue and cheek tone can work, it’s just a really bad idea.