5.) Добро пожаловать на персональный почтовый ящик Ивана Иванова, компания «Вася Пупкин и Ко». Пожалуйста, оставьте сообщение и свой номер телефона после гудка. Вам обязательно перезвонят. Для срочных запросов, пожалуйста, отправьте письмо на [email protected]. Большое спасибо за ваш звонок.
In my (US-based) experience, doctor offices & the like have a place where you can fill out if they can leave messages or not (and some even have asked detailed messages vs callback messages), so that's my perspective! And that I can set different things for different numbers. So my cell phone they can leave detailed messages on any matter, my mother's house phone is detailed from billing only and otherwise callback, her cell phone is callback only. (And they also aren't allowed to tell her anything other than billing, so even if she does call them back about anything else! That was just a measure set up when I lived with her one summer & had no cell reception at her house.)

19. "Hello, you've reached [your name]. I'm currently [exploring Asia, hiking through the jungle in Costa Rica, hanging out on the beach in Bermuda] — or more likely, [recovering from extreme jet lag, googling ‘Are red spiders poisonous,' or looking for SPF 150 sunscreen] and won't be back in the office until [date]. Leave your contact info and reason for calling and I'll get in touch then."
“Good morning. You’ve reached the voicemail of [your name]. Today is [date]. Please leave me a message with your name and contact information. Oh, and here’s my motivational quote of the day: [read quote].”