The bottom line is that a business’s situation is likely to change often and rapidly, each of which need a unique and applicable voicemail greeting to cover the circumstances and timeline. For example, callers shouldn’t reach a business-as-usual voicemail, and therefore expect a return call within the business day, if the subject they’re calling is out on vacation for two weeks. Such a lack of communication is a recipe to lose that caller’s trust and tarnish the brand’s reputation.
Voicemails need to maintain a professional consistency that’s aligned with the entity it’s representing. That said, the structure can vary depending on the situation. There’s no template set in stone. In fact, trite and generic should be off the table. The goal should be a balance of uniqueness and practicality.

Packages start at $50 for studio-quality, professional phone greetings, prompts & messages on hold.
Some iPhone owners are reporting issues with their voicemail after updating to iOS 11 or later. Instead of being able to listen to a voicemail directly on their iPhone, the Voicemail section of the Phone app instead prompts users to "Call Voicemail." An Apple support document suggests resetting your Networks Setting to return to Visual Voicemail. You can do this by navigating to Settings > General > Reset. Now tap "Reset Network Settings" and enter your passcode. Your phone will then reboot.