Help your users know when to expect a response. It’s easy to show customers your team’s availability and let them know when they can get assistance from your team. You can manage their expectations by setting your office hours and expected response time.
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.

Thank you for your email. Your credit card has been charged $5.99 for the first ten words and $1.99 for each additional word in your message. This message is automated because until [DATE] because I’m moving to [LOCATION]. That’s right. A cross country road trip from [CITY] to [CITY]. I’ll get back to you when we pull into the driveway.
Both your customers and your employees need to know how long your business will be shut down for the holidays. Provide notice well in advance. Depending on the types of services you offer, you may need to start notifying customers as early as a month out. It would be best if you were to provide these important notifications at least two weeks before the holiday shutdown. Employees should also be reminded regularly that the company will not be open during those important days.