Hoo boy, have I got some PTSD from Old Job about out of office autoreplies. Exboss was such a stickler for them and actually enforced her expectations as official policy. Meaning if you didn’t do it to her exact specs, she’d call you back to the office to do it (which no one did) and read you the riot act afterwards while threatening to write you up for insubordination. She demanded them any time that we were away from our desk for longer than 30 minutes and for anything other than a meeting. So training in the conference room down the hall, a work lunch with teammates, leaving an hour early for an appointment, arriving late for an appointment, even working from home, all required OOO alerts.
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.

Setting a proper out-of-office email also puts pressure off you when you have limited time to respond to emails outside the office. We will look at a few examples together here:
I work in a culture where even when you say you won’t have access to email, you are expected to be checking. I include this only on the internal auto-response, so that the people in my company know that when I say I won’t have access to email (which is also explained in the email), I mean it. Nothing else seems to work.