I saw a version of this on IG that was an old school (paper) OOO from an associate pastor. It has a line like “if this is an emergency and you must speak to someone, Jesus is always available on the mainline.” Too funny.
In most cases, the voice of your out of office message should be similar to the voice you’re using while communicating with clients. If you’re usually formal, replying with a joke could be jarring — and vice versa. Your mileage may vary, but keep that in mind before setting up an automatic reply.

Long Vacation Message. If you’re going to be on vacation for a week or two, then it’s essential you set up your vacation email. If you miss the odd day, the world won’t implode, but if people don’t know you’re away for a few weeks and they don’t know exactly when you’ll be back, or who they can contact in your place, you’re going to have some unhappy clients or customers.
What we need in our work communication is not more professional politeness or less formal, chat-based messaging applications like Slack. We need honesty. The problem is that we’ve conditioned ourselves to see honesty as self-indulgent or disrespectful. I’d argue the opposite is true. Honesty, even if it’s a bit more inconvenient for all parties in the moment, pays dividends later. It builds trust. When my partner Anne Helen Petersen and I were interviewing people for our forthcoming book on remote work, a frequent lament from both middle managers and workers was that they didn’t feel like they knew how to succeed in their jobs; that they were guessing what their superiors and coworkers wanted and, even when they asked, they didn’t quite trust the responses they got back.