Informal voicemail greetings are those that don’t adhere to the rules of professional and business voicemail greetings. Here, you are free to just leave a simple greeting, or use it to show your more witty side. This style of greetings can be used for both home and business if you like, depending on the type of caller you expect. For instance, a novelty shop could probably create a rather informal message, using sound effects that represent the type of items they sell.
It may sound silly, but the tone in which you say something can either play the professional status up, or it can bring it down. You can’t change what your voice naturally sounds like, but you can work on controlling it to make sure you sound calm and collected when recording your message.

Don’t rush. It’s important to speak slowly and clearly when leaving your next voicemail greeting. Have you ever called someone and the message sounds like one big word? Don’t be that guy. Pronounce your words and take pauses between your sentences
Humor also leaves a lot of room for misinterpretation—which subsequently weakens sincerity and authority. A caller can be very turned off by merely misinterpreting your joke. Why take this risk? Additionally, this could even cause callers to question your character. Say, for example, the president of a company’s mobile phone voicemail greeting was funny. What’s to happen if the caller didn’t like or get the joke? What if they found it offensive? Another scenario is that a caller is reaching out to you for the first time—i.e. they have no idea regarding your personality. What next? The point is, with this type of greeting, humor is bound to be more divisive so just avoid it altogether. c. Poorly Pacing Your Message and Bad Time Management: Don’t speed through your message. Speak clearly so callers know what to include in their message and when to leave the message. At the same time, don’t drag your message out. No one wants to sit through a diatribe. Just get to the point clearly.