Take note of this holiday checklist so you are prepared for the Christmas wind down. Remember that your office is your and your employees’ second home. Having these precautions done will give everyone a stress-free holiday break.
Be aware of your tone. Keep it clean and simple. Sullivan says: “Even if you work in a casual office environment, the people emailing you may not. It's fine to have a light tone in your communications, especially when you're in an email conversation with someone directly, but your OOO is more of a blast message—including a cat meme or silly quote could backfire if your OOO goes to, say, a new client prospect or the sales director at a company you've been trying to engage.”

Here is an auto reply message example that provides an alternative email contact option to assist customers during the absent period. Thus, helping customers not to make impromptu decisions and understand the next course of the move.
I’d add a little more detail to your message just to make it clear what will happen in your inbox. “If I don’t hear otherwise, I’ll assume that your issue was handled by my colleague” or “Please cc me if you contact Jane, and I’ll check back in on my return if I think your issue is still open.”