I used to work with someone who had a message telling people she only checked her email twice a day. You pretty much needed to call her if you needed anything outside of those times. (She worked in a remote office.) I think she had read one of those books on efficiency that recommended scheduled email time. But there were problems with this: 4. My department often had to email attachments or text to illustrate our questions/concerns. And we were on deadlines. Reading a page of text over the phone was not an efficient use of anyone’s time 5. She did outreach & was often out of the office on site visits, trainings, or travel to these places, but never ever set her OOO for these, because she was “working.” However, she was effectively not available to read emails from other staff until after hours on those days.
Yes, me too. It’s a lifesaver. Although to be fair, Outlook announces the fact that you’ve got an OOO message going out with a big yellow banner, so it’s quite hard to miss.

In my much, MUCH younger days, I printed out a photo of a cruise ship with an arrow and “I am here” pasted on it and taped it to my monitor…
4.) Benvenuti alla John Doe Solutions. A causa di un evento interno, il nostro servizio di segreteria non è disponibile oggi. Potete lasciare un messaggio. Saremo nuovamente al vostro servizio lunedì. Ringraziamo per la vostra comprensione.