Yeah, announcing you were going to delete emails unread and expecting the sender to resend when you return would NEVER fly in my office. I’d get executive complaints about that, especially if it went to a client or outside party – if a client can’t reach you, they will reach out to someone else who may not work at your organization and you lose business. I feel like this delete-it-all philosophy would only work for an entirely internal role where timelines are more relaxed, and even then, I feel it’s a bit unprofessional to foist your own catch-up work onto others, especially if they’ve been backfilling for you while you were OOO.
But that sounds boring, right? Luckily, there are ways to spice up your OOO message by adding humor in just the right places.

Being a responsible netizen or professional in the Internet age also means leaving useful clues and messages for your email correspondents whenever you will be out of reach temporarily or permanently. Remember that your email correspondents expect you to respond within minutes or, at most, 24 hours of receiving their emails unless specifically stated in the email that you are free to respond much later.
According to American Express, “Six in ten customers feel that companies meet their service expectations”. Customers look for faster resolution and rely on the expectations that businesses set with queue time for evaluating their service quality.