Expanding on the simple approach above, let the caller know who they've reached. This will not only eliminate people leaving voicemails by mistake, but it will reassure the caller that they have called the number they intended.
In 2011, I became a full-time sales coach and consultant. I push, challenge, and inspire top producing sales professionals to increase their income, manage their time, and love their career. I routinely help my clients achieve more than they thought was possible.

10.) Hello, and welcome to John Doe. For technical reasons we can not take your call personally. Thank you for your understanding. We are working very hard on a solution. If you want, you can leave a message on our homepage www.johndoe.de - Thank you and goodbye.
If it works better for you, offer your callers the option to email you, or even send over a text to a VoIP texting app, or even your personal number if you don’t mind. Many people will prefer the ability to quickly text or email, and callers will appreciate the increased level of service.