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.
I mean, this is what I pretty much did upon returning from my maternity leaves but I would never put it into an email! My maternity leave OOO was the vague “I am on extended leave and am not anticipated to return until X. Please contact Joe or Fergus in my absence.” X being a vague time-frame based on my due date and the length of my leave. No one is waiting 3+ months for an answer so I did get to delete most of the 500 emails I got during my most recent leave! I did once have someone internal tell me I should say maternity leave rather than leave, but really, what does it matter? I’m gone for a few months and no one outside of the company really NEEDS to know why.

See, if it’s a long period of leave and there’s an alternate contact provided, this is just… the sensible thing that should happen?
Education Details: 15 Out of Office Messages for Professionals. February 26, 2021. Out of office messages are automatic email replies, or autoresponder email messages, that go out to colleagues, customers and clients when you are away from work. They let others know you are unavailable for contact and when they can expect a response to their emails.