I have an email account that I forget about, now that I've got my new computer and don't have my old reliable email program anymore. It wouldn't work on Windows 7.
The email account is one that gets messages from various thing I signed up for over the years, but by and large it's been captured by spam people. So it's actually worthless.
I have another program that can check on it and delete things without actually downloading them. And tonight I'm finding out how truly good it is. I thought I had to download the headers at least for everything. But that was taking longer than I like. So I checked the options at the top, and, thankfully, there actually is an option for deleting all messages on the server.
"This cannot be undone," it warned, in words similar to that. "OK," I reply, "so much the better." Delete the garbage!
It's going maybe 10-15 every second or so, so that's not as fast as I'd like but still pretty fast. It's about halfway done. And I would guess I need to stay connected for it to continue. It'd be nice if it just kept going on its own but I'm not going to take that chance.