I have a confession to make: I haven’t recorded a new voicemail greeting since 2014. In the past four years, I (hopefully) have become more articulate, poised, and self-assured. But hear my voicemail recording, and you’d think I was still new to the work world, a little unsure of myself — and probably not an authority. Obviously I need toupdate it. And if you haven’t changed your voicemail greeting in over a year, you’re likely in the same boat. After all, a professional voicemail recording boosts your credibility, makes you seem more competent, and encourages whoever’s listening to it to continue the relationship. A relatively unprofessional one — like mine, for instance — does the opposite: It encourages prospects, recruiters, and potential connections to run in the other direction. With that in mind, I’ve written 18 unique voicemail greetings for every situation. Pick your favorite, practice a few times, then record your new voicemail.
In the case that your business is closed due to an emergency, it's only worth it to go into detail if the problem is affecting everyone in the area. Otherwise, stick to your Company Wide Voicemail Greeting, but remove the stated hours and tell callers that you're currently closed. Thank you for calling Cutlass Technology. Our store is currently closed. Please leave your name and phone number so that someone from our team can follow up with you. For more information, please visit www.cutlasstechnology.com

Reiterate the main point of your message and repeat your name and phone number. This will help the receiver remember your name and message and spares him from having to listen from the beginning to write down your contact information.
It's easy to get carried away in a voicemail and include more detail than is necessary. We've all been in that situation where the automated or pre-recorded voice on the end of the line goes on and on with more information than you can take in.