Ask HN: Are you requiring email verification during signup for your service? 8 years ago
I would agree with this assessment, but also add confirmation before you were ever to dispatch any email sent to the address.
I work for an ISP/services company and we require confirmation for everything.
Personally though, I abhor companies that allow account creation without confirmation. I have a gmail address that is my id, minus the first r in it. Over the years, I've received oil change notifications from people's cars, trip/hotel/dinner reservations with click-through ability to alter without supplying anything, rental agreements, billing, dating profiles, etc. that I have total control over because people are idiots. There has to be some kind of railing in place to keep lemming from leaping off the precipice.