Plus, he incorporated a delightful technique to let people know that if they really wanted him to read their emails, they should probably send them again after his return. Not only does that keep the sender accountable by saying, “If this is really important, you know when to reach me,” but it also helps him truly vacate his work while he’s away. And that’s hard to do. First, travel to my homeland of Florida. Climb to the highest peak of the tallest mountain. Find a rare flower (no specifics, of course… It’d be cheating). Put the flower back, because as the old hiking rule goes, “Leave everything as you found it.”
That’s what I always reasoned… better to annoy with too much information that saves hassle on the backend then be brief upfront and sentence people to OoO purgatory.

An out of office message could become an opportunity to connect with your client on a more personal level. Consider sharing something about yourself that they might not have known about while working with you.
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.