Here’s my OOO nightmare: when I was a graduate intern a few years ago, there was a volunteer with severe, marginally treated mental health concerns. Her behavior toward me was inappropriate to the point that my school assisted me with a safety plan. I obviously blocked her on everything I could think of. Unfortunately while I was on winter break she emailed my agency address from an account no one knew about, got my OOO message, assumed it meant I was open to communicating again, and proceeded to have a monthlong meltdown in my inbox when I didn’t respond. To this day I am grateful for my city’s utter lack of public transit, which prevented her from trying to find my home and family.
I had a manager who did exactly that for his paternity leave. I was floored, because I never thought it was an option. His attitude was that if it was important enough, the person would send it again.

We do OOO messages, but also send an email to the department and other relevant people, so that part doesn’t sound odd to me. I want to know if someone is going to be away next week, because then I can plan accordingly instead of sending them an email about something important Monday morning and find out I’m SOL until the following week.
19. "Hello, you've reached [your name]. I'm currently [exploring Asia, hiking through the jungle in Costa Rica, hanging out on the beach in Bermuda] — or more likely, [recovering from extreme jet lag, googling ‘Are red spiders poisonous,' or looking for SPF 150 sunscreen] and won't be back in the office until [date]. Leave your contact info and reason for calling and I'll get in touch then."