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.
Note: Sending automatic replies to anyone outside my organization will send your automatic reply to every email, including newsletters, advertisements, and potentially, junk email. If you want to send automatic replies to those outside your organization, we recommend choosing My contacts only.

I say this as someone who used to have a chronic problem keeping up with my personal voicemails. But I got voicemail transcription set up so I can read them now, because just ignoring important phone calls has consequences. I can’t imagine trying to just duck them in a professional job where I had a phone number, and therefore an expectation that people can call me!
For non-urgent inquiries during my absence, you can contact [Name] at [email] or [phone number], and they will be happy to assist.