If you are recording a voicemail message for business, be sure you include your name and your company's name, so people know who they are calling and were they are reaching them. If you do not include the business name, they may think they have mistakenly called you at your personal number. You will also want to make sure to give callers the option to speak to someone who is currently available, an operator or other representative, by pressing a certain key (check with IT personnel to see what this might be).
If you want them to leave a voicemail, tell them right from the beginning, “Please leave your name, reason your calling, and the best way to contact you.” If you want them to call you back during normal business hours, tell them, “Please call back during normal business hours.” If you want them to call back prepared for a lengthy conversation, you can say something like, “Please refer to our website’s FAQ page,” and then provide the URL. Self-service should never be underestimated.

* If you forget your voicemail password, there's no way to reset it from your iPhone. You need to contact your carrier to reset your password. If you insert a new SIM card, you might lose the voicemails that you saved on your iPhone.
5. Holiday Voicemail Greetings. Happy [X holiday]! You've reached [your name] at [X company]. I am currently out of the office, but please leave me your name, phone number, and the reason you are calling, and I’ll return your call after the holidays.