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.
If they are calling without an expectation that you always pick up (such as if you are a business coach or a one-man shop) then thanking them for calling might make the most sense.

25. "Hello! Thanks for reaching out to [company]. We're closed today for the holiday, and will reopen tomorrow. If you leave your name, number, and a brief message, we'll give you a call when we're back in the office. Thanks again, and have a great day."
How many times have you gone through the following scenario: While working with a customer or engaged on an important call, you receive a new voicemail. You listen to the message, hoping to understand the caller’s name and issue correctly. And when the caller whizzes through the digits of their callback number faster than you can write, you have to go through the entire message again. Once this exercise has been completed, you call the person back, only to get their voicemail.