4.) Bem-vindo ao Sr. John Doe. Sr. Doe está ausente de sua mesa no momento. Por favor, deixe uma mensagem que o Sr. Doe possa ligá-lo de volta o mais rápido possível. Muito obrigado pela sua chamada.
Your phone system can be a powerful marketing tool for your business, and that includes your voicemail greeting. If you want to utilize this opportunity to throw in a quick humblebrag and keep callers informed of your awards and accolades, there are a few best practices, you should follow. First, keep the self-promotion brief and appropriately placed within your voicemail message. Don’t promote yourself and your products/services in the same greeting, and finally, only include current achievements in your business voicemail greeting.

Give them a reason to call you back. In both voicemail messages, did you noticed how I mentioned new information they might be interested in? That will grab their attention more than simply introducing yourself, thanking them and asking them to give you a call if they have any questions. Come from a place of helpfulness by giving them something to look forward to and that will solve a problem.
I could see an argument for relaxing that for mobile voicemail, on the basis that mobile phones are pretty personal and not generally shared by multiple people, but I've no idea whether that may have happened. Or, indeed, whether such policies may vary between organisations within the NHS.