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.
“Thank you for calling [company/person’s name]. We are currently unavailable, but if you leave your name, phone number, and message, we will get back to you as soon as possible.”

For those with voicemail greetings that get changed about as often as a new president is elected, know that this is doing a serious disservice to the caller-recipient relationship. It signals to callers that the business is anything but an authority, most likely not very detail oriented, and has questionable overall credibility and competency. Those aren’t traits that any business wants to associate itself.
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.