I have no idea how to update my voicemail message and I don’t actually know what it says. I occasionally get voicemails that are automatically forwarded to my email as sound files but I don’t think I have ever had a business related voicemail land there (it is rare that I get calls from outside the company and most people in the company if they can’t reach me on the phone will IM me directly–we use Teams for both phone and messaging).
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.

Optionally, if you want eDesk to send the auto-response at a random time, you can also configure the maximum delay field. In this case, if you set a minimum delay of 1 and a maximum delay of 4, then eDesk will auto-respond with this template between 1 and 4 minutes after it received the message.
Same. I’ve been out of the office for over a year and did not change my voicemail message on my desk phone, nor have I checked it in that year. To be very honest, I didn’t usually check it even when I was in the office.