One thing that happens when you regularly send a newsletter out to tens of thousands of people is that you see a lot of automatic Out Of Office (OOO) email responses. The most common one I receive goes something like this: Hi, I’m out of the office until __ and may be slow to respond to email. If it’s an emergency, you can reach me at __ or please contact __. Thanks!
Over time, I began to suspect that those who might be telling the truth (of which I suspected there were very few), would mention their relationship to the person and possibly the cause, for example “My grandmother just passed away after surgery.” The ones who left it wide open (“someone close has recently died”) led me to imagine that it could be a random person in their city that they read about in the news, their goldfish, or perhaps a distant relative who had passed away in the previous few years.

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.
You might receive multiple emails from coworkers and clients if you’re not specific about your absence dates, which will clog your inbox and make it hard for you to remain productive when you get back.