There’s a grim, apologetic vibe to these messages — I’m sorry I’m taking time for myself but I’ll try to check in on occasion! They’re a vivid reflection of a work culture that valorizes constant productivity and the near-total overlap of work and life. But they’re also do a terrible job of what they’re intended to do, e.g., set realistic expectations for both sender and recipient. A vague OOO message traps both parties in an uncomfortable liminal space where both productivity and rest go to die. The original sender is left unsure if they’ll be getting a timely response or a whether the email will go ignored for a time or forever. The original recipient has taken what is a rock solid excuse (time off) and cheapened it, offering a backdoor for email guilt to creep in.
Meanwhile, I do sometimes put up long ones when I will be away for some days during a season in which there are a confluence of three or four very likely reasons someone would contact me, and who else they need to contact isn’t the same. Like, it’s high llama grooming season, and generally during this month I get two or three requests per week for each of llama bleaching (for which my backup is Stella), llama shaving (for which it’s Arturo), and llama perming (for which it’s Carter). My message says I’ll be out until blah blah, and if it’s not an urgent llama grooming issue, I’ll get back to you after that, but meanwhile, for urgent llama grooming here’s who to call.

Thank you for your email. I’m out of the office and into the cookies and eggnog right now. I’m celebrating the holidays with my loved ones and will not be checking my email until [return date].
(first line in the second one refers to the new exec for our function starting that same week – an internal move). If I can get the date I’ll be back into the haiku I do, otherwise I put it afterwards, along with the person to contact in my absence. Obviously if I’m off sick or otherwise can’t be bothered I don’t do the haiku.